Only upload the Assets and Project Settings folders
Load these folders on this repo in your project, these folders contains the meta data needed so that this repo won't cause problems on cloning and working on the project on different devices
These files also contains the Audio Manager, the Audio Manager is a prefab, whenever you want to add new sound, just go the Audio Manager prefab in your scene and increment the sound array, you will find an extra place added so you can add you sound, please be carreful you have to use the same name of the sound as C# is sensitive to this shit.
Whenever you want to push and update the repo, the best thing is to clone the repo somewhere else, and whenever u want to update, copy the two folders (Assets and Project Settings) of your unity project and replace them with the already cloned ones in the repo folder, and then push.