I am starting a business online selling things and I would like to know kind of questions should I add to my FAQ page, or should I wait to get feedback from people before I make a FAQ page.

I would not wait I would go to your competitor's sites and see what questions they have in their FAQ and just rewrite the answers and questions.

I agree you should just try to anticpate the types of questions that you will get, look at your competitor sites and other sites that are not even in your field to get ideas.

Good luck with your new site! Make sure you post it in the website review section so you can get feedback on the site.

What we do is ask some friends to review the site and ask them what questions they may have regarding the product or service we are offering you can get a great head start on the types of questions your clients may ask.