How do I have a members only forum and a general population form. In other words, I'd like to have a general Q &A forum but also have section where clients an have a password protected discussion forum, etc.
You can set different access to different forum. So you can have a public Q&A forum and private forums which will be accessible to usergroups you want. Here is the way you can create a private forum: https://gvectors.com/how-to-set-up-private-forum/
Note: all forums and categories will be on the same forum page, but the private forums will only be visible for selected usergroups. There is no way to have different forums in different pages.
Also, please read this topic to understand how the forum accesses and usergroups work in wpForo and how to manage permissions: https://wpforo.com/community/faq/wordpress-user-roles-wpforo-usergroups-and-forum-accesses/