You learn as you start playing and reading tool tips. Start looking at what actions require combos and positions etc. The main problem that I see with new players and old a like, is that they get a new action on there bar and dont read it, "oh its there let me push the button" sort of reaction.
Be aware, when you doing a quest or doing a dungeon, try doing your combos and buffs while going through this game. Have fun though while doing it, see if i move and hit the enemy on the side, i do more damage, or if I use this move i get a buff that makes my attacks hit harder for 30secs etc. All about being aware :) Ask some players in game aswell or friends you have made, if they are rude or are assholes ignore it, and move on.
