Hello
the .git-folder is in the same folder as your experiment. Look here for an example. Notice that it is hidden. But since you already deleted the .gitignore-file you know how to find hidden files. There is no .git-folder on Pavlovia.
What projects do you see when you use the Find existing studies online) button (blue magnifying glas, third button from right)? Filter the authors by selecting Me
Best wishes Jens