Q. gives you the option to be a member of more than one team. This is very helpful if you are working for more than one organization or need a separate space within your organization.
To join a second (or your 3rd or 4th team) you can just create a new team and invite your colleagues and friends. It is of course also possible to invite people into an existing Q or be invited into an existing team yourself. In this case you just need to accept the invitation.
To switch between you teams, click on your profile picture in the quick action bar and select "Switch Team". Now you can select the team you want to switch to.
Remember that if you are in multiple teams you can only use paid power features in teams with a paid subscription.