Line with AA

[Jazzy3113]

Full ring and I just sat down for two orbits. Alot of medium and short stacks and very aggressive. I bet on sports and they opened a poker room, so its small but filled with pure gamblers.

I am UTG with obv AA and limp. Hijack, button, sb limp and bb checked, so eff me.

Flop is rainbow K high with two low cards. I check, button bets pot and all fold. I think making a call or raise here is fine and I just call.

Turn is another low card and would make a one gap straight of like 57 or something, s basically a gutshot got there. He bets pot again and I call.

Now the river pairs the 4 or basically one of the low cards.
Board looks something like K 2 4 6 4.

My question is does the 4 help or hurt my hand? It does counterfiet a king two pair hand. Is there a good chance he is bluffing and I should only make a post oak bet? Can I only lead if I am able to fold to a reraise?

I obv ended up misplaying the hand and would also appreciate general feedback on how to aaproach the rest of the hand when you limp with AA, KK and have to take the flop like this. Calling the flop is ok, but can you fold turn to a PSB?

Gracias