Teams

You create teams per company. Go to teams via the menu on the left. You will then see a button '+ Create team'. Name your team and you're done.

Team manager

Only after you have created one or more teams you can link your managers to the teams. If you have several companies and you want to give the managers access to them, first create the teams for all companies. When adding or linking the manager, you can also immediately select all companies to which this manager should have access.

You can read here how to add a manager to eveHRyday.