I ordered a iPhone 12 pro and I can’t find the tracking number

Yes, that would be the order confirmation email. There will be another email when the item ships. In the meantime, you can check the status of the order by accessing the “Order Status” link from that initial email. If it is a recent order, it will probably state “Order received” or “Processing”.

If you purchased a phone 3 days ago and you don't have a tracking number, the phone HAS NOT SHIPPED. When you placed the order, Apple gives and estimated deliver date range. What did you order say for when the phone should be delivered? It would say something like October 29th - November 6th (as an example).

The order should say:

Processing

Then it moves to Preparing to Ship

Then it moves to Shipped

When it actually ships, you'll get a tracking number.

NO. No one on this forum works for Apple. Use the order confirmation email to check on the status of your order. But honestly, given that MILLIONS of people have ordered iPhone 12 there's a high probability it hasn't been shipped. And again, when it DOES ship, you'll get an email.

No one here can find anything, as we are merely other Apple product users. Using the initial email you received, click the “Check order status” link.

Has the phone been shipped?

Have you received an email from Apple, notifying that is has shipped? If so, the link for tracking will be in that email.