Newbie in Heroku: Error when push my app to Heroku

You cannot push any random repo to Heroku. It has to be a rails app ( or any of the other supported apps like Django, but in this case OP is working on Rails) and that is what the pre-receive hook is rejecting in your case since your repo just has some dummy file. ( NOTE that the first step in the tutorial is not creating an empty git repo, but creating one for your Rails app. See the output in the successful push example in the quickstart - Rails app detected - means it looks for the rails app when you push something.)