To gain a lot of points, play a lot, like 3 to 4 hours a day, Medic on Karkand only servers. See how much fun you have doing this for, say, two months. Then see if you still want to have many many points or to play for fun, or maybe to play diverse roles or play on unranked servers (with more teamplay) to get better. Being good has little to do with points, try it the other way, play to get better (train close fighting, after you got good at that try killing tanks with Spec Op or AT). After the round reflect on what you've done, find the weaknesses in your play (like charging in on enemies too early, pick fights with too many at once, little teamplay), and read some of the fine Guides to better play on this page, which show the common sense one will develop after truely trying to be better at the game.
One example for a fine guide:
Teamplay GuideYou will find more fundamental guides there, too.