Hello guys. I just created a game and I want to upload it here. Is this possible? What should I do for that?

Errr... is it a PC game? Google only returns Android references when searching for VaultXStudios.

"I just created a game...". Wow, you make it sound so easy.

"This morning, I took a shower, ate some breakfast, fed the cat and created a game, before running to catch the bus. A productive morning, my cat seemed content."

It is possible to create a game within a few minutes. Can't tell about the quality of said game, though.

By using Engine like Unity3d and Unreal you can export for many platforms (there are still things that you need to code for each platform like input from touch screen or mouse... But for the most part is the same code).

To vault:
Anyway usually gog don't publish any games, just really old games, triple A and indie made by big companies and big crowdfunding.
I suggest you to use steam (of course) where you only need to pay 100 dollars one time, humble bundle (at least the widget) and itch.io

If you use unity remember to export your games for mac and Linux (and test at least the Linux version),