Is it a scam

• Apple does not send such messages. 
• Apple would not warn of a pending account issue, giving you a deadline to fix the issue. 
• Apple does not include document, or PDF files to download.
• Apple would not refer to you as Dear Customer, Dear Client, or anything other than the name on file for your account.
• Apple would not have such horrible spelling or grammar. 
• Apple would not send a message to “Undisclosed Recipients”. 

It is a phishing attempt. Do not respond. Do not divulge any personal or financial information. You can use the address below to forward the suspect email message, as an attachment to Apple.

reportphishing@apple.com

The links below has information to help identify fraudulent emails.

Identifying legitimate emails from the iTunes Store

https://support.apple.com/en-us/HT204759

No. If there was someone signing in from an unknown device, you would see the two-step authentication popup on one of your logged in devices. There's definitely no warning to verify the Apple ID.

As stated: it is a scam email. Ignore it, as you should with all such messages.

To add to the list stedman1 stated, another one is:

Apple does not ever include links to verify your account, cancel a purchase, or similar.