As for questions, what I’ve seen is stuff like “what did you think of [thing that happened this chapter]?” or about a specific character, or “what do you think is going to happen next” sort of questions
Some others (including myself) dedicate a separate chapter for author notes and questions for readers
Other books with more expansive worldbuilding even do glossaries, maps, or extra chapters for other stuff
Example:
There’s a lot of flexibility in what you can do (or not do, if you choose!) with your book on WP