Hi all, i am new here, i am a bit stuck with some uni work and hope someone can help as i am getting a bit confused.

I have been given an assignment, it is a hotel booking system, we have been given a invoice to perform some RDA on.
In UNF, i gave the customer details a level of 1, Booking details a level of 2 as customers can have more than 1 booking, and booking-extras a level of 3. i think this is right, but im not 100%.
one more thing that is confusing me is that i am currently trying to convert from 2NF to 3NF and i have got CustomerID and BookingID as a compound key in Bookings, but also i have Room number (FK) as it is relevant to the booking. now room number (as far as i can tell) is not at all dependant on the primary key, so it shouldn't be here, but i need it in the bookings table... im confused.
Please help??
i can send you a screenshot of what i have if it would help?

Thank you.