Tips for a beginner player:
1. Expect to die. A lot. (in game of course.)
You are new to the game, and unless it is release day, other people aren't. They know more, they've learned tricks, they've studied game play patterns and can start to expect when/where things will happen. You can't. You are at a major disadvantage. Keep playing, observe, and every time you fail/die, remember to not spend the time simply watching the spawn counter, but ask yourself "Why didn't that work?"
2. Become familiar with the controls.
Ideally do this off line. Figure out how things work, how your character moves, and teach yourself to be able to do basic controls without thinkings about them. If you're thinking "Wait, what key makes my character go prone again?", you're likely about to go back to tip number 1 very soon.
3. Set small goals.
Starting off a new game, especially a style of game you've never played before, with the idea that you'll be the best in the server isn't going to work. Set yourself small goals at the start. "I want to get at least one kill every 5 deaths." or something like "I want to be in second to last position on the board, instead of dead last."
Remember the game is team based, and you get more points for aiding your teammates. Hanging back isn't too bad if you're brand new to the game, but keep an eye out, figure out the goals of the different maps, and then start moving toward them. You'll use tip 1 a lot, but eventually you'll figure out the maps and begin to do better. The goal of RO2 is to get your butt in the correct zones, and keep it there, while keeping the opposing team off the zone.
Even if you can't hit anything, you can still help your team win by simply sitting there adding to the cap/defense score.
Also, remember to press ctrl (use) when you come up on a friendly machine gunner. 5 free points, and he keeps shooting. Win Win. Just remember to not run in front of him right after giving him ammo.