Welcome Ddelisle, congrats. First mod should be harnesses and a harness bar. From there, whatever your budget can handle. Try and get in the habit of changing the fluids in both the front and rear diff at least twice a year, more if you're hard on your machine, or the terrain is challenging. Check wheel bearings, ball joints, and especially the bolts / nuts that hold on the rear trailing arms to the frame. Even if they look good, I recommend changing them out, they are possibly stressed.