Assault and support are good classes to start with, and one more thing, newbie doesnt means noob, it maybe a bit disadvantage for you to start with few weapons and unlocks, but when it comes to game, teamworks and secure team score are more important than K/D ratio.

I enjoyed when i was a newbie back then, haha, everyday can unlock new weapons, can get excited of the next unlocks, chill bro, gaming for fun~!