How is the workflow between Github, local server and Openshift Online?

Issue

1) I have created an application (Anahita) - by using composer, and it is now running on my local server, ready to be deployed on a public server. I would like to deploy my applications on Openshift, but I have had challenges to understand the workflow so far. I need to find out as soon as possible if Openshift is the right solition for applications that needs to be created and maintained using composer on the local server. If it is not possible, I simply need to move on. Is it possible to push from local repo to Openshift if there is not first created an Application on Openshift?

2) If this happens to be possible - in what local directory should I push from, what Openshift repo should I push to - if there is not already an app on Openshift - and what is the comand?

3) If it is not possible to push to Openshift without first creating an application on Openshift, - but I still need to Install and maintain my local application using composer, how should the workflow be like?

4) Is it OK I share the information in this thread with other people in the Anahita community - as I believe there are other members also courious on Openshift?