Hi! I am completely new to ionic, and have been roaming in google looking for tutorials/walkthroughs on converting an existing MEAN Stack application into Android using ionic, but most of these tutorials left me confused and I’m nowhere near getting it done. 
Can someone please direct me to the appropriate steps? It’s a bit urgent. Thank you.
MongoDB, Express, Angular and Node.js (MEAN).
Ionic + Angular -> Progressive Web App
Ionic + Angular + Cordova -> Hybrid Mobile App
Check this tutorial video:
This is an old tutorial based on AngularJS and Ionic 1 but it shows you how to build a full stack app on Ionic.
The same method can be used to build Ionic apps with MEAN stack capabilities.