Hello and welcome to the QuickBooks Online community!
It's awesome that you're working on customizing your sales forms to help your business stand out for your customers. QuickBooks Online makes it easy to add your logo or even change up the colour scheme of your invoices and other forms. I'm happy to say that you can also change the column order! Here's how to do it.
Select the Gear icon in the upper right of the account.
Choose Custom Form Styles.
Click Edit on an existing style or New Style to create a new one.
Navigate to the Content tab.
Select the middle section of the preview on the right-hand side.
Click and hold the 9-dot box beside a column checkbox and drag to rearrange.