Yeah, medic is a good kit to start with... but try to learn other roles like AT (Anti-Tank), MG (Machinegunner), Breacher... so when you join a squad that already have 2 medics you can fill other roles in your squad.
Try to learn how to:
deduce distances so you can be accurate with HAT, LAT and Granadier
find good spots to lay down for some seconds so you can be efficient on where you "set up shop" with a machinegun
be quick and have response times so you can fast and deadly with the Breacher's shotgun or quickly rope overwalls so your squad can aslo be quick
And then when you get such an ammount of experience that you feel comfortable using anything try hosting a local server and play around with the vehicles so you can move to the next step, the best one: Armored Warfare Death from above and Transport