Safari disappeared

You can’t find it in the App Store because it is impossible to delete and therefore there is no need to download it again. If you use parental controls with Screentime or restrictions, you can restrict Safari which will make the app disappear.

Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support

You can look for it with a Spotlight search by swiping down from the middle of a home screen and typ Safari into the search field.

You can also Reset the home screen layout which will return the app to the home screen but will destroy app structure and folders on the home screen. Settings>General>Reset>Reset Home Screen Layout.

You’re welcome. I’m glad that you got it all sorted out.

First of all I failed to understand, how did you manage to delete Safari.

Have you installed any software which is prohibited, unauthorised.

Only way to get it back is

Settings > General > Reset > Erase All Contents and Settings.