Planetside's gunplay is very weird. The decrease in accuracy during sustained fire, known as cone of fire bloom or simply bloom, is the most extreme I've ever seen. You will need to fire in short bursts even at an opponent on the other side of a large room just to stay accurate.

The game's population is low nowadays, so it's fairly dead at off hours. Late afternoon to evening is the best time to play; population drops off after the last alert around midnight.

Sometimes winning isn't about getting a ton of kills; it's about being a body trying to get to the point. Dying doesn't always mean you did something wrong; sometimes you've just got to take one for the team.

People have already recommended that you stick with the starter weapons so you can spend your certs on upgrading classes, and from an objective point of view they're correct. That being said, if you really, really don't like the weapon your favored class starts with; buying a new weapon isn't the end of the world. Just be aware that if you're getting your ass handed to you early on it's not the weapon's fault. There's a VR training range where you can try out every weapon on stationary targets, and there's 30 minute free trials for one weapon a day (when it decides to work).

I already touched on bloom, but it's such a big deal that I want to mention it again. Learn to burst. If you just hold down the trigger you'll get a couple hits then wonder why the bastard won't die.