Normally, all visitors to your Authory page will see all your articles in chronological order. They can then select to see one of the Collections you have created.
However, you can also decide that visitors to your Authory page shouldn't see all your articles but a certain Collection instead by default.
To mark a Collection as your default Collection simply log in to your Authory account and then select "Collections" in the sidebar menu. You'll see a list with your Collections. Next to the name of each Collection is a star icon. Click it to make the respective Collection the default one.