Sounds like a few of you guys need some help. I've been playing Planetside off and on for about three years now, so I can lend some tips (regarding my style of play, that is).
1. Your first certification should be the Mosquito. It is the fastest vehicle in the game, and a practiced user can easily mow down hordes of infantry in moments. It also gives you access to the roofs of bases and towers, allowing you to get a jump on any unsuspecting snipers.
2. Your second should be Heavy Assault (with the Medium Assault prerequisite). It gives you the edge you need to compete in close range infantry encounters, which are extremely common once the fight inevitably moves indoors. Remember to move your draw distance slider (found in the graphic settings, I believe), all the way down to increase your frames per second.
3. Third should be engineering. This will allow you to both repair your armor and the armor of your mosquito. You can recover health with medkits, which are free for all characters.
4. Your first implant (at battle rank 6) Should be either Adv. Targetting, Surge, or Audio Amplifier. The first lets you know the health of the enemy, the second will save your life if you find yourself in a situation that you need to get the hell out of, and the third will let you see incoming enemies on radar.
That should give you a solid character foundation to start with.
On to loadouts.
1. Always have a REK. Always. No exception. You need it to get into any enemy base, and without it you look like an idiot.
2. If you do not have medical, I suggest a loadout consisting of a Rek for pistol slot 1, a BANK (engi tool) for pistol slot 2, the MCG for rifle slot 1, and six medkits coupled with three boxes of 9mm ammo. This is a fairly solid indoor agile suit loadout, so long as you spam medkits like a madman during every fight and re-arm at nearby terminals constantly.
3. For outdoors I'd take out a few medkits, add in an extra box of ammo, a jammer grenade, and a cycler instead of the MCG.
Misc tips
1. Always use third person (press the T key) to look around corners to get the jump on approaching enemies.
2. Right click on an item in your inventory (IE, a REK) to rapidly swap it for one in your corresponding "1" slot (ie, a BANK). This will save time and your life, as fumbling about trying to piece it back in your loadout takes far too much time.
3. Armor piercing ammo (gold ammo) is only for maxes. Don't use it on anything else, for despite the description, the damage done to other vehicles is negligible, and will at best alert them to your position.
4. If you see a max indoors, and you don't have the proper anti vehicle weapon (The decimator), run. Getting surge will greatly increase your chances of survival in this situation.
5. When flying, save your afterburner (the space bar) for when you are either missile locked, getting hit by flak, or in a dogfight. If you have no afterburner you are a sitting duck.
6. If there is enemy aircraft outdoors, stay indoors or near a door you can rapidly run through. If you are outside as infantry with mosquito's roaming about, consider yourself dead.
7. Don't get in a galaxy with a pilot you don't know. You will probably die right as you bail out of it and hit the ground.
8. When in a mosquito, always tilt the plane far to one side before you bail. This will remove the bail animation and allow you to shoot as soon as you hit the ground.
9. Outfits that invite you without speaking to yourself are probably crappy outfits that will make you a crappy player. Deny any outfit invites until you have played with them first.
10. Excessive use of Plasma Grenades, Maxes, or Personal Shield is frowned upon.
11. Blowing the generator or camping the tubes are no no's. Don't do them.
That's all I can think of at the moment, I'll update this later. Send a /tell to me ingame with a question and I'll help you out.
Planetside Name - Fortress-E
Outfit- Delta Triad
Empire- Vanu
Server- Gemini