How do I link my databast to my custom login form?
I tend to keep title in place, but you can set another field to be the primary and then delete the title.
As for ID, there is one automatically created - you just need to reveal that column in your collection. I believe that is internally indexed within WIX for rapid access. Don’t get primary field confused with primary keys (index lookup) as whilst in some cases they may serve the same method, the primary field is the main display field for the collection and used for reference fields.
Some more info
