Force registration / protected content

I have a new client that is looking to setup a website with daily fantasy advice (basketball, football NHL, etc.), but wants to limit the content to paid subscribers.

So I want to know if it is possible to setup the theme to require a force registration page where the user/subscriber is required to login before having access to the website content/front-end. That way his lineups can be protected to only people who have a paid subscription.

He takes of the subscription via PayPal, so all I need to do is setup the force registration page as soon as the user types in the domain. I can then create a video to show him how to add new users via the back-end as he acquires more subscribers.

Also, is it also possible to change the logo of the login page from the standard WordPress logo. This isn’t as important, but wanted to know if it was easy enough to change..

I just wanted to make sure this was achievable before purchasing another theme for this specific project.