I need help with the AC pulley it making squeaky noise when the bolt are tighten up but the pulley doesn't spin so the belt is just burning.. I bought a brand new bearing replace it out and it doesn't run smooth can somebody help?

 

you are missing a washer in the idler pulley.

there is a small washer inside the bigger disc that sandwiches against the inner bearing race,

it likely dropped out when you took it apart, picked it up and wondered where it came from, and didnt figure it out and forgot about it.