Basically Im running a campaign with all newbies and made characters for them based on a few things they said they wanted. I want to be able to share the sheets with editing enabled so they can add final details like their description and backstory, but I seem to be unable to do that. Any tips? Im new to dnd and beyond as of this week.

I think you should be able to add the characters to a campaign and then assign them to the players in question.

Yeah, just give them to the players by making a campaign and adding the characters unassigned. Then they can join, claim, and edit their characters.