I've had some trouble when I have a good hand and am facing a raise from UTG. I feel like when I 3bet I fold the hands I am beating.

Two examples, vs unknowns.
Assume 100bb effective stacks.

UTG raises, SB calls, I call with JJ in the BB. 3bet? I would vs a MP or later raise but UTG shows a lot of strength, but on the other hand, playing JJ multiway isn't ideal.

Second example: UTG raises, I am in the small blind with AQ. I called, but I had no idea. Fold? call? raise? Also on this hand, I hit an ace. At that point is just check/calling generally reasonable, or would you consider a raise? I felt a raise would generally fold worse hands and get better hands to call.

Obviously players and the particular cards/flops matter. However, I am asking for general advice for the situations I described if possible because I am often facing unknowns, and also can't supply hand histories from bovada (looking into card runner)

Like you said it's very situation and opponent dependent.

Against someone that folds a lot to 3bets you are folding almost everything that you beat indeed. When you are only vs UTG and UTG is taggish or nit a call seems reasonable to me. But, if there are some cold callers in between I like the squeeze a little better, you a folding the best hands of UTG still, but there's lots of dead money in the middle.

On the second hand, it's also a call IMO.

in general i dont 3bet JJ vs an utg open vs unknown. Same goes for the AQ. Until i get info that they either fold fold a lot to 3bets or call light pre, calling in both situations would be my standard aswell.