Before you can publish your app to the Apple App Store, you need to enter the information which is used to show your app in the Apple App store.
In the Publish dashboard you use the App Vitals section in the bottom right corner to fill in your App Name and Icon.
The splash image is the screen which is shown when your app is loading and is not required.
Edit store info
In the Publish dashboard you use the Apple App Store > Edit Store Info to describe your app in the app store.
Fill in all the information in this screen.