I also want add email address and phone number to shipping address from, I disable the billing address form, since I am using for payment paypal and strip , and dont’ want collect billing address info
in the checkout form ,there is a link for registered user to login and already once he login in the same page , the shipping address got populated with customer’s shipping address in file, but for not register customer ,I have the setting once he choose the payment method, and click on place and order, got errors for all shipping address fields , once he fills in , it either take him to paypal, or place the order if he choose credit card and fill in the credit card info
I want in this step register the user, have check box in the shipping address form, ask him to you want to register, if checked, add his shipping address, so need extra fields email, phone number to register him, but will register only with email, and I set the password in register customer to generate, I know that is different, but what is the best practice for this scenario

Thanks