Menu Roles and Users

How to select the role with which I want to enter if I have several roles??

You can assign any set of roles to users of your application.
Typically, users with low privileges are assigned to a small number of roles, for example one or two.
Typically, users with higher privileges (for example, admin) have more roles than regular users, or even all available roles.
What role you assign to users depends on the specific application.
The roles of user affect the content of the menu, and allow access according to the access rules defined in routes/web.php
However, the set of existing roles and the rules of assigning roles to users,
as well as the contents of the menu and the routes/web.php content - depend on the specific application.