How do I find out which model iPhone was my first iPhone

You can review email messages

Otakumom wrote:

I can’t remember when I bought my first iPhone. Can I find out which date I first made my account?

Have you tried contacting your carrier? If you still have the same one, they might be able to tell you when you activated an iPhone on your account.

No.

Unfortunately not. As another community member shared, you can visit your email and attempt searching through there. Other than that, there's no other way to check.