The most popular way to start trading cryptocurrencies is to open an account with a cryptocurrency exchange. Cryptocurrency exchanges are websites that allow you to buy, sell, and trade cryptocurrencies. You will need to provide personal information to create an account and you may need to complete additional verification steps depending on the exchange. Additionally, you can also sign up for a brokerage account if you prefer to have a more traditional trading platform. Finally, you can also purchase cryptocurrencies from peer-to-peer networks, such as LocalBitcoins.