It's nice to have you with us in the Community today, @9130 3486 4601 6776. I'm here to make sure you can get that invoice printed on one page.
You can make invoices fit on one page by resetting the margins.
Here's a couple articles about using invoices in QuickBooks Online which may come in handy:
Visit me here again in the Community and keep me posted on your progress with this printing issue. I'm determined to help you succeed.