Teams are groups of users that can have up to 50 members. You can find them at the fourth icon of the lower bar of the game.
There are different ways of joining a team. Once you access the tab, you will find a search tool in which you will be able to enter the name or code of the team you wish to join.
You'll also see a list of teams looking for players and you'll be able to join the one you want. You will be able to see the team's name and the number of members it already has.
Lastly, you'll be able to create your own team. Once you choose that option you'll have to enter the name, emblem, add a description, choose the type of team and its location.
Once you join a team, you'll be able to see its members and a ranking with their respective levels. If you wish to leave the group, you'll have to press the arrow located beneath the team's box and tap on the "Exit" symbol.