I don't think you are stupid
1) In your web browser, create a free account on GitHub.com
2) In your web browser, create a New Repository. Initialize with a ReadMe.md (it'll be an option).
3) Download and install GitHub Desktop
4) In your web browser, click on Clone... in your Repo.
5) Pick a folder where it'll download through Github Desktop. It should be an empty folder.
6) Copy your Mods folder into it the same folder.
7) In Github Desktop, click on Summary text, and enter in a description: "First upload"

Submit.
9) In Github Desktop, click on "Push origin"
Edit: The smiley with the sun glasses is unintentional, but it is an exciting moment when you submit your changes.