How to allow access to data based on relations of the current auth'ed user?

Hello, I found out about Strapi a few days ago, and I’m building a proof of concept to bring it to other projects I work on.

For instance, I want to bring a simple data model:

We have Posts. Posts have an author (User), a title (Short Text) and a content (Rich Text).
And we have User, that is the default model that comes with Strapi.

What if I want a user to be able to DELETE only the posts that it’s the author? What if I want to deny read access to the posts for every user that isn’t its author?

I feel like this question has been answered plenty of times, but I can’t find it anywhere in the forum or GitHub. So sorry if this is a dupe, it probably is…

Thank you so much, hope I can get a solution for this to start using it in real products