Access denied for user 'rodrajrybnik_2'@'%' to database 'rodrajrybnik_2'
The database server could be connected to (which means your username and password is okay) but the
rodrajrybnik_2 database could not be selected.
rodrajrybnik_2 have permission to use the
username_rodrajrybnik_2. Could that be the problem?
If you do not know how to set up a database you should contact your host. If all else fails you may find help at the WordPress support forums.