Jeez, you're as impatient as the children!
It's kind of a pain to explain because there are a lot of steps.
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Go to github.com and create an account.
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Download Github Desktop from there to your computer, and install it however your OS installs software.
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Open Github Desktop's preferences and teach it your Github login and password.
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Now, in Github Desktop (hereafter GD)'s File menu, choose "New repository." Give your repo a name and decide, or let GD decide, where on your computer to put the repo. Publish your repo. (GD will walk you through that.) Remember where it lives on your computer.
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Drag files, such as your 10Mb project file, into the repo.
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Find the "Changes" tab on the left in GD. Click it.
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The files you dragged in should be there. Down near the bottom, put a one-line title for this set of files. Since nobody else is contributing to this repo, the reason doesn't have to be sensible. Once you have that done, GD will let you Push your changes to the repo.
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Your project is now available for all the world to see! You just have to tell them your Github username (not your password of course) and the repo's name.
If any of these turns out to be too terse, ask again.