Trying to implement a hotel booking system in rails

I am building a hotel admin app that will host locally for internal use
to track all room bookings and direct a bill to booked room, very
minimal functionalities. I have created a table for one room that gets
booked, which isnt working because a customer might want to book
multiple rooms. How can I implement a booking system if I have a
customer model, rooms model, bills model & book_room model for booking
form “which isnt working for me”… I tried adding multiple columns for
multiple rooms but It feels very low level.

heres my github repo: GitHub - MrAbalogu/hotel-admin: Hotel Admin for small & medium sized hotels

heres a link to the app: