You can add questions to your registration form under Tickets > Question / Form. If you would like some questions only visible for certain types of tickets, please select the box that says "Show this question only for specific ticket types".
When your attendees go to register for the event, these questions will be within the registration form.
Once people start registering you can export your order responses to see their answers to your question form. This is found under Tickets > Orders > All Orders > Download list as Excel.