Is there a source out there where you can get or get access to databases already filled with information?
Not in general unless you count all the poorly administered SQL Servers out there.
I'm not sure what you mean. If the admin did not keep his info secure? So there aren't for example any free databases that have all of the every county in all the states anywhere.
There are sources for that kind of public data but I don't know of anything beyond Google that I would call a registry of them.