Hey,
Knowing other classes skills and animations are really important, nothing helps more but playing those classes yourself. Since in GW2 you can go sPvP at 2lvl after tutorial zone, just try some classes yourself. Is there any specific class you having problems with?
Also, S/P is not the best wep set to deal with everyone, but if you like it, keep using it. You will run into people who say it’s useless and trash, but what is more important is having fun.