Buying and selling cryptocurrency can be done through different methods depending on the exchange or platform you use. Generally, buying and selling is done through exchanges such as Coinbase, Kraken, or Binance, where you open an account, deposit funds, and then buy or sell the cryptocurrency of your choice. You can also purchase cryptocurrency directly from individuals or traders through peer-to-peer or person-to-person exchanges such as LocalBitcoins or Paxful. In addition, some platforms have begun offering cryptocurrency ATMs and even brokerage services that allow you to buy cryptocurrency without having to set up an account.