The app store is the only application that I am aware of that you can't find through spotlight search. You can search the app store directly from spotlight search, but it will never list the App Store as an app. Very annoying.

I just opened spotlight and typed “ap” and App Store came up as the first option.

Thanks for this comment. I was able to fix this issue, finally. Had to toggle the switch in setting> apps> App Store > search and restart my devices. :)

I thought it was some legal thing about App Store competition.