To create a second account, you'll be using Parallel App to clone that app. Once it's cloned, you can enter the app and create a whole new account for yourself! Just follow these steps:
1. Install Parallel App
2. Tap the '+' button inside Parallel App app, in the top-right corner
3. Select any app in which you'd like to create a second account
4. The icon for this app will now appear on the main page of Parallel App
5. Tap the new app icon in Parallel App; this will launch a new instance of the app and allow you to create a second account!