Users specific dashboard and strictly assigned cpt/category/...

Hello all, good morning,

I have a question related to users and groups. I think I really need some expert advice here.

I want to make a landing page like theme for our little village. Activities can be announced there. But I need some user restrictions on that. I explain:

E.g. the local bike shop and the local pub.

When the local bike shop user logs in, on his/her dashboard, he should only see the new/edit/... (crud) actions of one specific custom post type and some general fields like name, contact person, url, ... No themes, statistics or any other content.

Same for the local pub. But of course the local pub doesn't see the items for the local bike shop.

My noob level is unfortunately way to high on figuring out the best approach to this.

So, any tips and advice welcome. What is the best approach to get this done?

Thank you all.