I have a folder with VS Solution with few projects and so on. I've created a GitHub repository and uploaded the contents of that directory via the web interface.
Now, changes have been made to my projects, and I want to start pushing those to my github repository. So I use
"Updates were rejected because the remote contains work that you do not have locally."
git pull RemoteName master
git fetch RemoteName
git merge RemoteName
git merge RemoteName master
You have two unrelated projects. One on github and second on your hdd, because you copied files only via web browser without git commands. Try this - backup your project on hdd to another directory and then delete project from directory, which you want to synchronize with gitlab. Then in your directory write command
git clone your_link_from_gitlab. The project downloads from gitlab to your hdd and will be synchronized.