Once your database has been setup, you can get to phpmyadmin by going to the db’s url, eg db_host.domain.com.
Or you can login to SSH and import your db by typing
mysql -h dbhost.domain.com -u username -pPASSWORD db_to_import_to < backup_file.sql
(you’d have to be in the same location as your backup_file in this instance)
Note that the password is next to the -p switch.