I want to merge two projects: one for React frontend and another for NodeJs Express backend. I'm using Android Studio to preview my front-end application on the mobile emulator. I'm not sure if you have any ideas on how to make everything work together.

I first copied the frontend project and placed it in the root directory of the backend project. I then set a variable in the package.json file to be able to start the frontend from the backend ("client": "cd my_frontend_project && npm start"). As for next steps, I'm lost and I really don't know what to do. Should I create one file to initiate this connection or multiple files since I know my project contains multiple pages/functions and how do I set up this connection?