Hello Amir, I was doing a little more research and I think all you had to set was under the authenticated user role, edit and view mrbs bookings. To prevent all users from making reservations you add email addresses to the area room you want booked
from Scheduling link click on admin-> edit specific room, add email addresses to form field. If you leave it blank, everyone can book.
Did you have any luck getting multiple days to work?
Eric