From Bitcoin to Dogecoin, thousands of cryptocurrencies exist and are available to purchase. However, not every crypto exchange offers them all. Before diving into a crypto exchange, make sure it has the coins you're considering. If you ARE looking are smaller altcoins or meme coins, understand that these aren't offered on many exchanges, and usually for a good reason.
Different crypto exchanges store your cryptocurrency in different places. Some keep your crypto within an online account, whereas others allow you to keep your crypto yourself. Many people believe that if it's “not your keys, not your coins,” but for beginner crypto investors, online storage can be a good idea.