Factory A/C operational question

[D-Day]

My truck had factory air, with the system still mostly in place besides compressor (took it off years ago). Haven't really thought about putting the stock system back to work till now... My question is, if I put a new compressor back on, what would need to be done to get it operational? I was under the impression the old A/C systems used an outdated/banned refrigerant, and would have to be retrofitted to use the newer type. Bit clueless here.

Would it be relatively simple and cheap to get going again? Be nice to use part of the factory system than a $1,000 complete system kit...not sure how you go about charging the older systems and whatnot.