Can someone help me put the App Store icon back on my iPhone?

The App Store app cannot be deleted from the iPhone or the iPad. I suggest you do a search for the app, and it should show up in the search results, and if in a folder, it will identify the folder. You can also look through your folders to find it. Last resort would be to go to Settings>General>Reset>Reset Home Screen Layout. While that should get it out where you can see it, all other folders that you have created will be eliminated and you will have to create them over again. If you had restored your iPhone to factory and set it up as new, the App Store is usually in a folder named Extras, or something similar to that. I've not seen it in a while.

Then I would go to Screen Time, and check to see if you have Restrictions set for the App Store. That would be the only other reason that it would be missing.