How I can delete a release that I added without deleting the artist I Just added
Depends. What’s wrong with the release?
If it’s a complete mistake you can fin the “remove” link on the release page. Unless the release is the only info added for the artist (e.g. no external links or other relationships) this won’t remove the artist.
If the release has some mistakes, but is not completely wrong those mistakes should just be fixed.
If it’s a duplicate it should be merged, not deleted.
artists will delete when there is a “blank” page. no getting around that.
Only if it’s completely blank. As paulakreuzer noted, an artist with no releases or recordings will still be preserved if it has any relationships or external links attached.