Hi
1. Purchase history
Confirmation of transactions is provided in due course via your card / bank statements, just as it would be if you were using the payment card directly.
If you are not provided with a physical receipt when paying via Apple Pay in a store, then you can ask for one, just as you can if using the same underlying payment card directly.
Apple Pay does not provide receipts itself via email or any other method. As part of the built-in security and privacy features, Apple Pay does not collect any transaction information that can be tied back to you. Payment transactions are instead between you, the merchant (or the app developer for payments made within apps) and your card issuer.
Information about recent transactions is provided to Wallet by your card issuer. Instructions for viewing recent transactions are provided here, under the heading "How can I check my recent transactions?":
About Apple Pay - Apple Support
2. Card number
You are correct in understanding that, when making purchases using Apple Pay in stores, a transaction-specific dynamic security code is included as part of the information that is sent from your iPhone to the store's payment terminal.
However, the Device Account Number - which is unique to each combination of payment card and the device to which you have added it to Apple Pay - does not change either over time or depending on where you use that underlying card via Apple Pay.
The last four digits of the Device Account Number can be viewed on your iPhone and, if necessary, shared with a retailer when returning an item.
Instructions for accessing those digits are provided here under the heading "How do I return an item that I bought using Apple Pay in a store?":
About Apple Pay - Apple Support
More information:
Apple Pay security and privacy overview - Apple Support