You finished it! Congratulations! That's awesome! I've been following you for some time.

If you're using Microsoft Visual Studio, simply change your mode from "Debug Mode" to "Release Mode" and then compile your game. This will form a "Release" folder in your project. Any files (Images, Sounds, Videos, etc.) need to be put in the Release folder. Then, put your Release folder in a zip file and attach it to your post.

If you want to share your code, simply take all your coding files (.cpp and .h files) and put them in a zip folder, then attach that folder to your post.

Cheers :)!

A good place to post it is the Your Announcements section of GDnet.

Also, if you want to continue improving the game, want to make it open-source and want people to post bug reports, services like github to host your code and latest build is very important.

Don't worry if it is a beginner's project. It is good to start building your portfolio out of these simpler but personalized games.