How do I get the camera icon back on my home screen?

When you tap any of the other icons, see if you get a little popup that shows more than one icon together in a folder. If you do get that, and it camera icon is in there, all you need to do is ‘tap’ and ‘hold’ the camera icon and then drag it out of the folder and put it back on the screen itself.

In this manner, How do I get an icon on my home screen?

Touch the Apps icon to display the apps drawer. Long-press (press and hold) the app icon you want to add to the Home screen. Drag the app to the Home screen page, lifting your finger to place the app. A copy of the app’s icon is now placed on the Home screen.

Furthermore

Beside above