If you are buying BTC for the first time, do not try to do everything perfectly on day one. Use a well known platform with clear rules, buy a small amount, and learn the basic buttons like deposit, buy, sell, and withdraw. In the US, Coinbase and Kraken both explain how to set up two factor security with an authenticator app, and it is worth doing that right away instead of relying only on SMS.
Here is a simple process that worked for me. Open the account and lock down security first with a strong password plus an authenticator app. Then fund a small test amount and buy a tiny bit of BTC, not altcoins, just to learn how orders and canceling work. After that feels smooth, do one small withdrawal test to make sure the address is right and the transfer lands, then think about adding more.
For safety, you do not need a long list of rules. Just remember one basic point. If you are using a self custody wallet and anyone asks for your seed phrase or recovery phrase, that is a major red flag. Exchanges will never ask for that. It does not matter if they claim to be support.
For platforms, you can learn on Coinbase or Kraken first, then try a small comparison test on something like BYDFi if you are curious about their lower trading fees or occasional fee promotions, and then decide what you want to use long term.
Just my personal views, hope this helps
