With launches you can both:
You can navigate through the structure of your launch from:
The Page Editor:
Select Navigate to open the structure of the Launch in the console:
You can also:
The Launches Console:
If you select a specific launch, you can then select Manage Content:
The Sites Console:
If you select a specific source page and open References, you can then select Launches followed by Manage Content:
You can also select Launches Console to access Manage Content (and other actions).
All of these entry points opens the launch in the Sites console, where you can:
To add new pages to your launch:
Select Create to create a page as usual.
To remove pages from your launch:
Select Delete to delete a page as usual.