i was full master league 1vs1 2vs2 3vs3 4vs4 so i play a descent level on sc 2. To be honest with you sc 2 is one of the hardest game to be good, you need a lot of pratice, but first try to have a good micro (army management) and macro (build & ressources management). it s important also to learn the basic like phoenix counter muta , marauder counter stalker , marine counter imortal , and you need to have a good vision of your openement it s nice to check him the more often you can, so you can adapted your units mixts for counter him. I was not pro but i have play against specialy in bnet :), so trust me this game is hard, when i was good at sc 2 i was playing only this game!