1. Do they require any form of identification to use? Like a passport or ID card
In addition to what OmegaStarScream said, it will get to am amount of money that KYC will be needed. But with low amount of money, only phone number verification may be needed.
2. When you want to buy or sell with it, does it have P2P trading? Or does the ATM and bitcoin belong to a company, and you're simply buying from or selling to them?
It is not P2P but the owner of the ATM knows how to deal with buyers and sellers.
You either buy or sell coins to them and some people will sell as you buy or otherwise.