You do not need to login to use Primo VE. When a patron is on campus within your database IP ranges, they will be able to get to all the content that they need without logging in. However, there are several reasons to encourage patron login:
You can use either internal or external authentication for Primo, but the best user experience is to set up external authentication through your campus IT, so that users have a consistent login experience across all campus systems. If you allow community borrowers to use Primo for requests or borrowing management, you will probably need to set them up with internal authentication. See How do I set up Authentication for Alma/Primo for more information.