Migration Joomla

Hello, unfortunately the migration is not going well. I'm trying the other way.
Clean installation of Joomla. Which tables from Joomla 3 do I need to transfer?

Yes, I took the tables from the old database and tried to upload them to the new one, but it didn't work.
Then I found out that I installed the PRO version instead of the FREE version before the migration update.
Then I found out that I lost the possibility to go back to the FREE version and actually destroyed my databases.(???)
Now I do everything by hand, it's fun, especially when it doesn't work as it should.