Here's the link to the section you need in the training portal: https://dovetailmktg.kartra.com/portal/mgsitlogin/post/164
This is NOT a necessary step at all. You can definitely skip this entire section.
If you want to use a domain name like www.yourwebsite.com without a path to direct to a main page this video will show you how to do it.
If we are building your automations, this is something you would do AFTER the automations are all built, not before.
For clarity's sake, a path in the URL would look something like this: www.yourwebsite.com/quiz
A main page without a path would look like this: www.yourwebsite.com.