i lost my app store app on my iphone 4 can anyone help me find it

Check your Settings app under General > Restrictions. I bet it's just disabled.

you either moved it into a folder or onto another page

It's probably there. You're most likely just having a hard time finding it among all your other apps.

Swipe left on your Home Screen until you get to the search page. Type Settings into search. Then tap on the Settings app within the search results. Many people who use large numbers of apps use this method instead of trying to remember where on which screen and in what folder an app might be hiding.