commit and push existing project to github

I am trying to commit and push an existing project from pycharm community version to github. Although I marked all files using "Git>Add", in the Changes list they are not visible, and when I try to commit and push the whole project no changed files are detected as changed in my project folder, only an empty folder is created on GitHub. When I create a new file within the project it is detected and can be commited and pushed, but I want to commit and push all my old files first!
When I delete the empty repository on GitHub and try to clone my project I get the message that the project is already on GitHub - and nothing happens. I have been trying now since an couple of days and just cannot figure out what I am doing wrong. I am thankful for any help.

Heidi