I need App Store for my iPhone

If you can’t locate the App Store on your iPhone, you might accidentally put it in a folder, because you can’t delete the App Store.

Access the Spotlight Search by swiping down from the middle of the screen. Type in “App Store” and search results should present you with an app and the name of the folder it’s in.

If no, force restart your iPhone.

In addition to what sergekills mentioned, it may have been turned off in the settings. Go to Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases and make sure Installing Apps is set to Allow. If it is set to Don't Allow then the App Store will not show up on your device.

Read the response from anypats above.