Some ways of buying bitcoin from the USA in these articles. You can take a look there.

1. How to Buy Bitcoin Legally in the U.S. - Investopedia

2. 9 Exchanges to Buy Bitcoin & Crypto in the USA

And these are some ways of buying bitcoin without KYC

1. Best Ways To Buy Bitcoins Without ID (How To Buy Bitcoins Anonymously)

And I also  suggest you to aware about KYC.