How do you get App Store if you don’t have it

Try looking for the App Store app in the App Library. If it is there (and I doubt that you can delete it completely), it should be possible to re-add it to one of your main screens (what Apple calls "home screens").

Find and use your apps in App Library on iPhone - Apple Support

It looks like in the European Union, it is actually possible to delete the App Library app (not just remove its icon from your home screens). If you live there, and you did that, see the section on "About deleting the App Store app" in the second Support article here:

Remove or delete apps from iPhone - Apple Support

Delete certain built-in apps from your iPhone or iPad in the European Union - Apple Support