I have a Blackberry Classic and a couple of weeks ago I started to get a message that some applications require a BB password. I never use any of thos applications so I ignored it. Now its prompting for a password I never set up and has locked me out of my device
In many cases, folks go through setup and don't realize they enter a password at the beginning.
I would try the password for your BBID first. Also go to Settings/Security and Privacy if you can.