As an admin, you are automatically assigned the first paid license in the Office account. You can edit your information to change to a free account. If you want to add more licenses to your account, see Add Licenses in your RingCentral Account.
If you have added additional licenses, you can assign them to new or existing users in the RingCentral app. You can also assign licenses when adding users. You can do this during the setup process after account activation or by going to the left-hand navigation bar.