My skateboard wheels are a tiny bit wobbly, is it normal?

Sounds like you need to tighten the nuts a little bit more with a 1/2 inch socket wrench. Try tightening them all the way down to the bearings, then back them off a little so you have some play between the bearing and the nut, about 1/8 of an inch. For the trucks however, try swapping out one of your wheels from the other side, and see if that fits, bearing could just be made too small or defective, if not, try filing down the spot on the axle. Hope that helps!!!!