I’ve packaged for shipping to , however I have no clue what exe to upload. I’ve tried the UE4Game-Win64-Shipping located in /binaries/Win64 but that always gives me a failed to open descriptor file.

This is something you should ask , there docs page seems to be very basic maybe there more info in dashboard for you to search? i assue descriptor file is something you need to make. Also you need to distribute whole packaged directory not only exe, your assets are store somewhere else.