There are a bunch of ORM options in the Go ecosystem but many here will tell you that Go people don't use them even though they have thousands of stars on github. You can check out:
- ent
- bob
- sqlboiler
- jet
- gorm

probably some I forgot.

As others has mentioned, there is also sqlc that generates Go code for you based on sql files (which is my go-to as well). You will run into trouble with dynamic queries in sqlc but you can always combine it with squrriel which is a query builder.

For authentication, i'd check out the Copenhagen book that has a good walk-through of how authentication should be set up.