Before starting, there are couple of things that needs to be installed.
Node.js
Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine and is is light and efficient. We will be using Node.js package throughout our tutorial.
Following is the link to download Node.js :
Expo
Expo is a developer tool with interactive gestures and graphics using Javascript and React Native.
Following are the links for Android and Apple:
Visual Studio Code
Visual Studio Code is a source code editor developed by Microsoft for Windows, Linux and MacOS. It includes support for debugging, embedded Git control, syntax highlighting, intelligent code completion, snippets, and code refactoring
Following is the link to download:
Genymotion.
Genymotion is the fastest Android Emulator. Most of the people will suggest to use Genymotion Emulator. Also, the developers provide support for various different versions of the Android operating system that you can choose from.
Following is the link to download Genymotion.
Using Device to run apps.
Expo provides you a way to run the app and test it directly on your device. It applies to both Android and iOS.
You can get a complete guide here.
If you still need help just comment below and i will get back to you.