What does Bubbles in the paint mean
Is that rust underneath?

Also if the door handle is broke on my 92 Lumina Z34 do i have to get a whole new unit

yes, bubbles under the paint usually indicate rust underneath. The door handle is an assembly, and aftermarkdet companies like Dorman and Motormite make them that are way less expensive than the oem dealer part.

What does Bubbles in the paint mean
Is that rust underneath?

It means you have some really fun bodywork ahead of you...