For Linux users :

First make the repository (Name=RepositoryName) on github.

Open the terminal and make the new directory (mkdir NewDirectory).

Copy your ProjectFolder to this NewDirectory.

Change the present work directory to NewDirectory.

Run these commands:

git init

git add ProjectFolderName

git commit -m "first commit"

git remote add origin https://github.com/YourGithubUsername/RepositoryName.git

git push -u origin master