How do I buy and sell cryptocurrency?  There are many ways to get into and out of cryptocurrencies.  Bitcoin ATMs are one way.  Cryptocurrency exchanges are another way.   The best way is very up to you and very dependent on where in the world you live.   One site (not affiliated with META 1 Coin in any way) that may help you is "Ways to Buy Bitcoin Worldwide" which lists per country ways to buy Bitcoin.

Every exchange is going to have a slightly difference user experience, but the process to buy and sell is very similar.