Editable page without dashboard access?

Are you referring to their Profile page?

No, to a Page (not Post) that they have created. Not their profile page. Is it possible?

And by dashboard, are you referring to actual Dashboard (wp-admin/index.php) or the entire back-end admin (Posts, Media, Pages, etc.)? I ask because I’ve heard the two terms used interchangeably.

If it’s the latter, then you’re looking for something more robust than Login Redirect. Off the top of my head and without knowing more about your goal, a membership plugin with a user-editable profile page may work well.

If I could keep them from seeing wp-admin/index.php that would be good. The site is for a club with each member of the club given a Page (not Post) to describe what they do. The “profile page” is irrelevant.
The goal is is to have the site administrator add a Page (not Post) describing each member, and later the member can log on and add new information about themselves on this Page about them. They should be kept from deleting this Page (the page with their personal and club information, I’m not referring to their “profile page”, which should probably be hidden from them too.) They should not be able to edit anyone elses’ Posts, Pages, or anything else. They should not be able to change themes, perform updates, or do anything else to demolish the site.
Posts are only added by the administrator.

So (whew) I hope I have the terminology clear this time! Is there any hope of doing this?