Do I only have to buy from exchanges?
To avoid doubt, you can buy bitcoin using bitcoin atm. But there are still only few bitcoin atm existing in the world. And for convenience, you can use mycelium to purchase bitcoin locally. There are exchanges like hodlhodl and bsiq, they are p2p exchanges with no kyc required, you can purchase bitcoin from such exchanges. But be careful, of scammers. But you not need to buy from exchanges, you can by from someone you know. You also need to be careful to avoid scam and harm.
Hello, I want to buy bitcoin, how can I be sure that they were not used for any shady business? If I buy directly from a person, what is the chance that I will have problems later?
Please, forgive my ignorance.
If the bitcoin transaction is already confirmed, you have not problem. But be careful.