Ampache currently does not support role based permissions. They are planned for 3.5.x. There are 5 user levels as of Ampache 3.4.x. They are as follows.
Guest
Read only access, guest users can look at the interface but they can not stream
User
Standard user can modify its own settings, stream music and use ampache. Most users should be set to this level
Content Manager
Added ability to make some additional setting changes not open to normal users