I cannot download any app on store

“It ain’t working” as a problem description also “ain’t working”. What happens? What doesn’t? Any error messages?

If you’re getting a message that indications your Apple Account is disabled in the App Store and iTunes Store, or “Your Media & Purchases account has been disabled”, you’ll need to contact Apple Support and resolve whatever issue has arisen here, for instance. Select your country or region here for the support telephone number: Contact Apple Support - Apple Support

There can be other things that block access to the app store. Being out of room on your iPhone can be another cause.