Minecraft servers are multiplyer worlds with cool games you can play games with other players around the world
to join a server click on mulitiplyer then click add server
it will ask you to enter a server name and an ip
the name for the server is optinal but for the ip you must enter the server address
the address you enter will determ the server
once you enter the ip click done then click the server
here are some servers that are great for people new to minecraft or just servers

1) minplex mineplex is a very large and one of the largest servers some servers are so big that they have diiferent ips for different places so to get to mineplex type us.mineplex.com or eu.mineplex.com

2)Hive, hive is a big server with tons fun games and great content ip play.hivemc.com

those are some great servers you can join and how to join them