Error: src refspec does not match any

The following will create a new branch in local and in remote as well. I follow this when I create a new branch to work with.

git checkout master

git pull origin master

git checkout -b your-branch

Make the new changes

git push -u origin your-branch

You don't appear to have a local branch named test1. You have a remote branch named test1 associated with your upstream remote.

You shouldn't be editing the upstream/test1 branch directly. In fact, attempting to check that out should have yielded a warning:

$ git checkout upstream/test1

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.

You should instead first check out a local branch that tracks the remote branch, which ought to look something like this:

$ git checkout test1
Branch test1 set up to track remote branch test1 from upstream by rebasing.
Switched to a new branch 'test1'

After doing this, an undecorated git push would push to the upstream remote, while git push origin test1 would push to your origin remote. Adding the -u flag there would switch the tracking branch so that instead of tracking upstream/test1, your branch would track origin/test1, so that future git pull and git push operations would refer to that remote branch (origin/test1) by default.