Fetching user roles on client side

You can get the logged user details, including role, by filtering users query by the logged user id. This is already explained in the documentation: Getting Details of the Logged In User and Binding them to your page
You can then use conditional regions in app connect and show / hide them depending on user role.
Security enforcer is for protecting whole page only. Conditional regions used the way explained above should be used if you want to show/hide elements on your page.