Hi e11eca,
You can access both your WooCommerce and bbPress through a single account. So any registered user would not have to create different accounts for the forum and the shop.
Here is a blog post on the integration on WooCommerce and bbPress to create a paid forum.
bbPress WooCommerce Integration: Tutorial on How to setup a Paid Forum on WordPress
This i’m sure will give you in depth information on what you want.
