Folks have put a lot of good info in this thread already. If you want a one stop shop for tips like these, check out
my guide if you haven't already. It has details on stuff like stacking buffs to deal with dispels, making javelins, clearing aggro with casters instantly when they're casting on you, strafe running, gear suggestions, and more.
For your scenario specifically, the single most important thing you can do to be a better puller right now is get more levels. Yes, this will take time, but it's also the thing that you should be spending your time on. Since raids (and Velious zones in general) usually aren't a good way to get exp, it would be higher impact in the long run if you sat out of a few raids to level up and started raiding again at 60. (To be clear, I'm not saying that making a beeline to level 60 would be the most fun solution, and EQ is a game. So, raid if you want to, but it's not the optimal solution to your problem).
Your next priority should be getting your epic. This will give you lots of MR, a junk buff, and more push for casters. Plus, getting your epic is fun!
After that, you can worry more seriously about gearing up, getting clickies, getting elder beads, etc. Gear would help in the mean time, but honestly, the time it takes to farm up money for serious gear upgrades isn't worth it when you can get more impact out of getting levels (though cheap gear like the resist necklace from LGuk or a Mantle of Absorption might still be worth it in the short term).