Why can’t I download anything

Account verification is a somewhat nebulous term Apple uses. It could mean you need to check and also make sure your Apple Account information is up to date -->  https://account.apple.com/ . However, in 20 years of having an Apple Account I have never seen this so I suspect it goes beyond that. If you are seeing this message as part of wanting to download something from one of the stores, see if what they mean is "verify payment". Add a payment method to your Apple ID as outlined in: Add a payment method to your Apple Account - Apple Support .

On an iPhone:

Open the Settings app.

Tap your name.

Tap Media & Purchases, then tap View Account. You might be asked to sign in with your Apple ID.

Tap Manage Payments.

Read the support article for how to do this on other platforms.

It could also mean:

Identity verification for Apple Card or Apple Cash

To protect your account, you might be asked to verify your identity when using Apple Cash or applying for Apple Card. Read in this support article how to do that. --> Identity verification for Apple Card or Apple Cash - Apple Support

If neither of those help, refer to this page for Apple Support features ➔ Contact - Official Apple Support

If the presented options do not resolve your issue, keep experimenting with any series of selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

This page has telephone numbers for contacting Apple for support and service ➔ Contact Apple for support and service - Apple Support