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 not compulsory 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 no problem. But be careful. Check the link below.
https://bitcointalksearch.org/topic/m.550002126. Meet in Person
There are some ways bitcoin can be bought or sold locally, the counterparty can request to meet you personally before making any trade. This can be very dangerous as the counterparty can rob the buyer or seller. Also, another issue is exchaning fake fiat for bitcoin. Certain precautions must be followed in a way no one will scam another. Using p2p exchanges to escrow the funds will be a good option, and also all possible things you can think to make the exchange successful is good, like having a bodyguard around.