With regard to library access, I am a university librarian and it is typical for university library buildings to be open to the public. Even when ID is required to enter the library, there’s normally some way to sign in as a guest even if one is not affiliated with the school.
Policies on what materials a guest will have access to in the library building and what (if anything) they’re allowed to check out will vary from place to place. It’s common to allow local residents to sign up for a university library account, although it’s also common for their borrowing privileges to be more restricted than for students/faculty/staff.