Everything starts with a problem trying to checkout your repository master branch:
git checkout master error: pathspec 'master' did not match any file(s) known to git.
Trying to checkout origin does not improve things, but at least is a step forward:
git checkout origin/master Note: checking out 'origin/master'. You are in 'detached HEAD' state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches by performing another checkout. If you want to create a new branch to retain commits you create, you may do so (now or later) by using -b with the checkout command again. Example: git checkout -b <new-branch-name> HEAD is now at d1389fef9... Merge pull request #4
Now, problem, your master branch is detached in your local.
Solution, create a new branch from that state:
git checkout -b temp
And point master to that new branch
git branch -f master temp
Now you can push to your origin branch to update also in github or your remote repository.