I have no experience at HTML I need help designing a sales invoice
All information shown on your sample is available on the default sales invoice with the addition of a custom field for your Notes and Comments. If you want this specific format, you will need a custom theme, which must be written in Liquid, not HTML. See https://www.manager.io/guides/10366.
If you don’t have the programming skills, hire a local programmer to do the job for you. This is not a coding forum. Users are responsible for their own custom themes.
Do you have any new design
Did you read my previous response?