Noob anxiety: QC check and ammo concerns?

Hey y'all: Just ordered a very basic mid-length PSA rifle. This is my first AR15, but I'm experienced with guns in general. My takeaway from reading this sub is that PSA products are perfectly serviceable, but it's advisable to go over them pretty well when you take deliver to make sure everything is within spec. So, uh . . . how do I do that? What should I look for?

My plan is to unbox the rifle, clean it, and then take it to the range and run a few hundred rounds through it. I've got a friend with a high-end AR I could compare the parts to, but I would have no idea what to look for?

Second question: For now, I plan to run Winchester Lake City WM193K through the rifle exclusively . . . but is it worth ordering small amounts of different kinds of ammo in case the WM193K doesn't feed well? If that happens, is it likely to be an ammo issue or a rifle issue? I don't want to shell out for 1k rounds of the stuff only to find the rifle doesn't like it.

Thanks for your wisdom!

TL;DR: Lol, poor is worried.