To see how the website looks when it is still on Drafts, open it up on a new window on the same browser that you are working on the website, otherwise, it will not allow you to see it; Draft website are not public, they are only visible by the event organiser profile who created them.
With regards to see a published website and test the registration as a normal user, if you want to keep using the same browser, log out first, and then go to the event website, otherwise, open the website on another browser that you are not logged in.
We recommend you have a personal account with which you can test tickets and registration processes as the event organiser account has certain rights that might make the site or the registration process slightly different.