Creating a database from a backup file
The RESTORE DATABASE command will create the database for you. 

Don't create it first because then it will have to be deleted by the RESTORE command and a type if safety check in there might not allow the restore unless you specify the REPLACE option.

Also, is the database in that backup was read only when the backup was produced, then it will be read only when restore. Just turn off that database option after you done the restore.