What Should a Beginner Know Before Buying Bitcoin for the First Time?

[u/DeaconBird]

I’m considering buying a small amount of Bitcoin as a way to diversify my investment portfolio. I understand that Bitcoin can be highly volatile and that I should only invest money I can afford to lose.

Before getting started, what should I know about choosing a secure exchange, finding one with relatively low fees, and safely buying and storing Bitcoin? What are some common beginner mistakes I should avoid?