How to restrict pages to subscribers only

Dear all.
First of all thank you for all the help you provide here! I know it’s not really an issue but I really wish to do this feature which I did like 3 years ago on another website but can’t seem to do it in this.

I wish to restrict pages to subscribers only - a sort of member’s area. I also wish that all those who subscribe get access to these pages automatically while logged in. I’ve managed to find a website that easily groups pages into a permission group however I need to manually add the permission to each user. Also I don’t wish to use the “private page” function as this would bring a 404 page if the patient is not logged which doesn’t really make sense.

Ideally free but if it’s a cheap plugin, I would go for it too! Thank you in advance!

Hey sorry I don’t think my question was clear.

This is the website:
https://mcfd-malta.000webhostapp.com/

I wish to create a member’s area with pages in the menu restricted from unsubscribed users. If the user tries to access such pages, they get redirected to log in or register to the website.

Hmmm is there anything specific for a Wordpress built website please?