How do I set up a connection to my GitHub repository?

Question

git

I'm not good at git, and I don't quite understand what I have to do to set up a connection to my repository. I changed ubuntu to win10, installed git in it, and as I understand it, I need to add the ssh key that is in my repository to the gitconfig file, am I right? Or do I need to create a new ssh key and add it to git hub, in which case I can work with old repositories?