Each booking generates a single invoice that includes the entire description(s) for the package(s) that are included on that booking.
When a package description is so long that it does not fit on the first page without breaking across the pages, the PDF version of the invoice will push the package description to the second page in order to keep the package description together on the same page.
In order to keep the package description on page one, you will need to shorten the package description.
Alternatively, you may be able to download the PDF and edit it directly, or convert it to a format that you can edit, then send the edited PDF to the client. You can then send the invoice through Check Cherry by clicking on the Messages tab in the booking, starting a new email and attaching the edited invoice.