In order to invite your teammates to your workspace, click on "Manage Team" in the bottom left corner of your dashboard.
Once you've typed in the email, you'll want to hit enter or add a comma to add more than one person.
Once you've added everyone, go ahead and click on Next to finish the process!
If you are on a paid plan where you're paying per user, you'll be asked to accept the charges for the new team members (at a prorated rate) on the next screen.
So no worries -- there'll be no surprises on your bill!