Need to turn WordPress into a paid subscription directory

I need to create a paid subscription directory where people can register their business and enter its details.

Subscriptions should be paid on a monthly or yearly basis.

Business details include typical fields such as: description, address, phone number, zip code, etc.

The idea is that people can create their user as usual, but all the data about their business should be entered in a custom post type. The reason I want this is because I can easily add new fields to a custom post type and also can assign different custom taxonomies, such as neighborhood, business type, etc

Question #1: how do I restrict each user to a single post? When a user signs up, a post should be created and assigned to his username automatically.

Question #2: I also need to offer paid membership per month or per year. How can integrate such a feature with a payment gateway, such as Paypal for example?

I don’t expect an exact response for these questions, but it would be great if I could get some guideance on where to get started.

Thanks!