Thanks for the answer !
so basically I need to restrict specific post consultation (not edition), to specific user.
Nothing related to admin/edition, just be able to see a specific post for a end user.
I was thinking of using ACF to help me doing that (putting user’s ID into a repeater field), but if you said it’s not the right way, I should maybe continue my research on how to do it.
But I want to restrict the post on my web page, nothing related to edition of ACF and/or edit the post, only admin will do that.