Hi, Muz123.

The Purchase Order will default to the Standard or Master sales form in your Custom Form Styles.

If you need to hide your email address and other personal information, you can follow the steps provided by my peer above and remove the check-mark for the email address and description.




Once done, the description and email address will be hidden on your purchase order upon viewing it. See the sample screenshot below.

The following articles are good references. These will provide you steps on how to process a purchase order from an estimate as well as steps on how to track and run purchase order reports in QuickBooks Online:
 

Create purchase orders in QuickBooks Online

Copy an estimate to a purchase order

Feel free to ask again if you have other questions. I'll be right here if you need anything. Have a lovely day!