My refurbished iPhone 12 won't download Facebook app

"Expired" means that the phone no longer has any warranty coverage, so you will have to pay for any service and repairs on the phone.

Not sure why you are calling this phone "new".

Try a Forced Restart on the phone. Follow the instructions very carefully, as this is a bit tricky. (Hint.....ignore the "slider" when it appears and keep holding the Side button in until the Apple logo appears. This might take another 30 seconds.)

Force restart iPhone - Apple Support

The iPhone 12 was discontinued in September 2023, so if your iPhone 12 really is "new", it has been sitting in a warehouse for over 18 months. This would not have been good for the battery.

So, it is much more likely that you purchased a refurbished or used iPhone 12.

If you tap on Settings > General > About

What does your iPhone say about Coverage?

I'm not sure how it could be a new iPhone 12? Apple discontinued iPhone 12 in September 2023. Can you download any apps? Do you see any error message when you try to download an App? Are you connected to Wifi or using Cellular when you try to download Apps? Do you have a valid payment method tied to your Apple Account?

Thanks for the clarification, but something is still not right. Even if you purchased a "refurbished" phone from an authorized dealer, it should have come with a one year or 12 month warranty from Apple.

The fact that the warranty has expired would mean that the phone has been used by someone for 12 months or more. Was that you or did you perhaps buy this phone from another individual?

When you get things working again, we need to check the battery status on your phone.

Bob Timmons wrote:

Thanks for the clarification, but something is still not right. Even if you purchased a "refurbished" phone from an authorized dealer, it should have come with a one year or 12 month warranty from Apple.

The fact that the warranty has expired would mean that the phone has been used by someone for 12 months or more. Was that you or did you perhaps buy this phone from another individual?

When you get things working again, we need to check the battery status on your phone.

If the phones model begins with a 5, it was refurbished, not by Apple but by an Apple Authorized Refurbisher. My understanding is it would have no warranty from Apple at all. It might have a warranty from the seller, but not from Apple.