First of all, go to github/gitlab/bitbucket and make a new repository
Now as we have our repository already on our local machine, so choose the second option
git remote add origin https://github.com/pjmouriya/test1.git
Now that we have added origin where we need to push our project files so use below command
git push -u origin master
Here -u, means that next time you don't have to specify name(origin) and branch(master) again.