Hey there, Asa_lee.
We understand that you’re unable to connect to the App Store app. You've taken some great steps already with your iPhone.
You'll want to follow the additional steps below from this article, if you haven't already: If you can't connect to the App Store, iTunes Store, or other Apple services
Use any Internet browser to connect to any website. If nothing loads, use another device on the same network to see if it can connect to any website. If no other devices can access the Internet, turn off your Wi-Fi router, then turn it on again to reset it. If you still can’t connect to your Wi-Fi network, contact your Internet provider for more help. If only your first device can’t connect to the Internet, get help with Wi-Fi on your iPhone, iPad, or iPod touch, Apple Watch, Apple TV, or Mac.
If you use cellular service to connect to the Internet on your iPhone or iPad, make sure that you have cellular data turned on for the app that you're using. To do this, open the Settings app, tap Cellular, then turn on Cellular Data."
If you continue to encounter this issue, you can contact Apple Support for further assistance here: Contact Apple Support
Take care.
