Deploy on Google Play and App Store

Since this is an expo app, the complete up to date documentation for publishing your project can be found here.
But in general, to simplify things

To publish Android App.

You will need Google Play developer account. 25$/once. Register here.
In your project run
$ expo build:android --type app-bundle
Follow the guidelines from expo, choose expo to handle the process. At the end you will get link where you can download your .aab file. This file will be around 50MB. But when uploaded on google play will be around 15MB.

To publish in Apple App Store

You will need Mac computer and Apple Developer account 99$/year. Register here.
In you project run
expo bi
Follow the onscreen instructions. Login with your developer account. After and .ipa file is made run the following command
expo ui
This command will upload the .ipa in your itunes Connect. First you will need to create an app there. The build will be available in TestFlight. And you can move it to be ready for review, and submit for review on Apple Review Team.

Does this looks complex

If this sounds complex for you, or you don't have Mac computer, we are offering Cloud App producer of the React App Builder, where we can make your app. More info here