A common beginner mistake is not purchasing planet population upgrades.  Until you've reached a sufficient development level, planets actually give negative income.  One upgrade is necessary for asteroids, two for full-sized planets.

Your top priority is to scout and learn the layout of the map.  You want to focus on expanding as rapidly as possible in the early stages of the game, with an emphasis of moving towards the enemy.  Once you start to get close, start building up military units.  Against the easy AI, you should have no problems outnumbering them 2:1 if you stay lean on tech, and crushing them from there is an easy matter.

As a rule of thumb, I like to colonize one planet every 3 minutes for the first 15 minutes of the game (this presumes a sufficiently large map and fast or faster game speed), which means after fifteen minutes I should have an empire of six planets.  This is, in my opinion, the bare minimum empire size needed to compete smoothly into the mid-game.  Any smaller and you have to start making serious sacrifices that are going to hobble you in the long-run, so if you find yourself with fewer than 5 planets you need to be very aggressive.

Need more details; there are horror-stories of top-level players online winning battles 10:1, but I've never heard of the AI achieving anything like this.  What sort of units are you up against?  What sort of units are you using?

yes i do all that stuff and still get my ass whoop and i try to build all the units like the anti aircrft with the long range missle units and crusiors i still lose. I also upgrade the shileds and weapons

i have the orngial and entrament both fully updated. i did svaed replays from a few battles but never starts at the begining only in the middle. (how do i upload? i know where the file is)

O really? i just maunal save the battle every time the game is done

o aright how do i upload it to this post?

aright thanks but ill do it tommorw got to get some sleep thanks for the info everyone

1) I recommend playing with pirates turned off when you're first learning.  When new players and the easy AI are involved, the pirates will essentially dominate whoever they attack.  Experienced players can swat down pirates fairly easily, as can higher difficulty AI's, but for beginners and lower difficulty AI's they're real game-enders.

2) Celenus Core is a somewhat more advanced scenario; it gives you very few defensible planets in close proximity to your homeworld, and forces you to over-stretch yourself early.  To play that effectively, you have to either run an aggressive rush game or manage a proactive interception defense game.  Not the kind of opening play I'd expect from beginners.  Try "Gaian Crescent", "Close Encounters", "Point Blank", "Face Off", or "Random Small".  Those are more straightforward.

3) It took you six minutes to leave your homeworld to start fighting the militia on your adjoining asteroid (that dead asteroid you colonized doesn't count; it has no economic value.  In fact, you should have ignored it until later and spent that money elsewhere).  As a rule of thumb, your adjoining asteroid should be colonized within three minutes.

4) You purchased a higher fleet capacity, and then didn't fill it with units.  Fleet capacity should be filled as soon as possible after you unlock it.  Either fill the capacity and use those units aggressively to capture new planets or attack the enemy, or don't unlock the capacity at all.

5) You invested too heavily in military technology.  Weapons and hull upgrades have their place, but this early in the game getting more units online and acquiring new planets takes top priority.  Remember that upgrades amount to a 5% boost (to ONE attribute) each; that isn't a big deal for small early-game fleets.

I'd also advise against the pulse weapon upgrades.  They only affect the Skirmisher, which is a very niche unit.  It's rare that you'll build enough Skirmishers to merit this upgrade, especially against the AI.  A good tech investment would be unlocking the repair platform.  It's relatively cheap (a little more expensive than a turret), but provides a whole range of utility from boosting your defensive units, to delaying attackers while your defenders try to arrive, to restoring capital ships to full fighting strength after a tough battle.  For a mere 400 credits, that's a must have item.  Even if you don't plan to build one, having it unlocked so you don't have to wait for the tech to research later is a very good idea.

Focus on learning TEC and Vasari.  Advent is very challenging to play online and beginners should avoid it (it's fine against the AI, though).

Most online games are played 5v5 or 4v4, and typically each player takes on a specialized role in the team.  For the most part, you'll be one of these three:

Aggressor:  Your role is quickly amass a large and threatening fleet and use it to pin down nearby enemies.  Economy is a secondary function for you, and your top priority is to keep the enemy occupied.  Even if you cannot defeat them, keeping them engaged prevents them from coordinating strikes against more vulnerable allies.

To be a good aggressor, learn how to perform and counter a solid rush game.  Focus on carrier capital ships and their abilities, plus the low-tech-level units.  You'll see a lot of the long range frigates and the flak frigates.  Good aggressors will attempt to dominate nearby oppponents by brute force, but if they can't get the kill they'll remain relevant by trying to bypass and hit other players and disrupt the entire team's operations.  Even if you're on the defensive, it's your job to prevent that, so learn how to be (sensibly) aggressive even when outmatched.

Defender:  You are positioned between multiple enemies, making your start location very vulnerable but also giving you the potential to be a thorn in their side.  Your top priority is to secure tactical worlds around your position in order to occupy the attention of multiple enemies.  You can't just sit back and defend, you have to keep their attention and try to give the rest of your team an opening.

You can't really prepare for the defender role by playing singleplayer.  Human opponents play siege battles very differently from the AI, and are much more likely to try to box you in and keep you sidelined rather than going for the kill.  Instead of trying to build the Perfect Defense (tm) you should instead focus on keeping the pressure on.  Remember, if the enemy can ignore you they will become an aggressor or economizer and will make life more difficult for the rest of your team.  You have to keep their attention and force them to keep you pinned down.  Good defenders can make or break games by holding out long enough for their aggressors to break through.

Economizer:  You are positioned safely such that allies cover all your flanks and can prevent enemies from easily striking you.  Your goal is to raise a large and powerful economy and infuse your allies with extra cash.  That means balancing rapid colonization, economic growth, and payouts to your allies as they are needed. 

To prepare to be an economizer, play some games on larger maps (possibly multi-star) and focus on rapid expansion and getting early trade networks online.  Good economizers can have absolutely insane income (100 credits per second by the 30-minute mark isn't unheard of) and that money will go to their allies who will pile on the hurt.  The economizer is very much the heart and soul of the team, and quite possibly the only role where your allies can't help you out.

Good luck, ZombieGod.  Hope to see you online in the future.  It's a great game, and human opponents really do take it to the next level (you haven't experience a starbase siege until you've been online).

After you have a starbase on your front-line planets, if the AI has to go through the star to get to you, putting 1 (or 4) in the star's gravity well is a great idea because the AI often doesn't attack it, and just moves through it while being chewed up. From my experience, anyway.

Of course, since they don't target the star-SB that often, hangar upgrades there are often more useful than usual.

A side-note: non-atrocious spelling and grammar is usually considered a plus when posting on forums.

Heheh, having played RTS games since I was a little kid I never pay much attention to these standard responses, but that is quite appropriate.

To put it succinctly, time is a resource in real-time strategy games.  Careful time-management is an excellent skill that will help you in other strategy games, and also in real-life.  I can't tell you how many group projects I've pulled out of the fire in the final hour because I can make efficient use of limited time under pressure, and that's a skill I attribute partially to years of playing strategy games.

another question when in combat what are good targets to attack the captial ship or missle units? or any other examples like flaking the enemy from behind?