Can't seem to find an app that is dowloaded in my home screen?

With iOS 14 apps can be removed from the home screen without being deleted. If you have iOS 14, go to the App Library (swipe left past your last home screen). From there you can touch and hold an app and slide it left back to the home screen.

If the App was moved to another screen, you can click and hold it until it wiggles, then you can move it to where you want it. If it does not appear on any screen, you can go to the App Store, find the App and then click on the small cloud icon to download the App again.