PvP isn't "difficult," just different.

Everyone is always moving around, especially when in combat. You have to be aware of where your team is, the enemy is, and the nodes are, so you have to check your map often. Your rotation changes from maximum dmg output to maximum burst output... stuff like that.

Basic rule of thumb is to stay with your team (bigger the group the better),learn how to dip and dive over the enemy line, and WATCH THE CHAT BOX. The number one reason for people doing badly in PvP is that they get too focused on what's in front of them and fail to pay attention to the rest of the game.

As for wolf marks, they are super easy to get. You make bank just for doing your daily roulette, and straight matches have a decent pay out. You'll have your hood in no time at all. If you start taking a true interest in PvP (Playing because you like it, not because you want the rewards), then you'll start raking in so many marks you don't know what to do with them. I'm still only at rank 46, but I can tell you that between ranks ~30 (started seize at around this rank) and 45 I'd gotten enough wolf marks to buy two full sets of the rank 50 gear, which is the most expensive stuff. Marks are almost never a concern. Exp... on the other hand...