Need help to install apps on iPad iOS12

iOS12 got rid of most of my apps. How do I get them back? And why can’t I reinstall form the app store? The app store only lets me open the apps but it does not install when I open them. Please help. Very frustrated, John.

I have heard that users have been able to reveal their hidden apps by resetting their home screen layout. Unfortunately, you will lose any folders and arrangement you created.
Settings > General > Reset > Reset Home Screen Layout

I have not experienced the problem, so I cannot vouch for the solution.

It worked!! The icons are in different places but I have all back.