To preview your registration page, there is a link just below your event title on your dashboard that says 'Preview'. Click here and then click on 'Registration Page' to see a preview of the registration. You may need to select a number of tickets from the numbered drop down then click submit. This will take you to the portion to fill in the order details.
You may notice that there is a 20 minute timer set for completing the order. The reason we have this is to prevent any orders from being claimed from the available ticket amount but not finished. If the timer exceeds the 20 minutes without being submitted, the order will end and that ticket will go back into the available pool of tickets so that someone else can purchase it.