To create a repository you need to open your Qlik Sense application and go to the Gitoqlik.
Specify the repository name and make the first commit. Each commit must have comment (short description of your part of work that you are going to save in repository)
Gitoqlik link repository with application in Qlik Sense by application ID. You could see that in the description of a repository.
You could commit the load script and app objects.