Simple steps to add existing project to Github.
In Terminal, change the current working directory to your local project.
##2. Initialize the local directory as a Git repository.
git init
Add the files in your new local repository. This stages them for the first commit.
git add .
or:
git add --all
Commit the files that you've staged in your local repository.
git commit -m 'First commit'
Copy remote repository URL field from your GitHub repository, in the right sidebar, copy the remote repository URL.
In Terminal, add the URL for the remote repository where your local repostory will be pushed.
git remote add origin <remote repository URL>
Sets the new remote:
git remote -v
Push the changes in your local repository to GitHub.
git push origin master
Pushes the changes in your local repository up to the remote repository you specified as the origin