It's pretty much like some other FPS computer games. Just play around and you'll get use to it, it's a pretty fun and strategic game. I recommend playing crackhouse deathmatch or dust2 deathmatch before you play eGO Highschool, so you don't have to wait minutes to play again. On a side note, if someone tells you to play jail, be careful!
*You gotta wait MINUTES (sometimes 10) until you can play again. And if you fail to do some orders, even touching your mouse, you gotta wait 10 minutes to respawn.*
That's pretty much it. Play Deathmatch server until you get use to it, then play some Highschool, Dust, Dust2, or office server. Then, play jail if you wanna see what's with all the buzz about it.
If you want, I can help you "sorta" play better?