Thanks for reaching out to us, @js12321. I'd be delighted to share some information about setting up your recurring templates for invoices in QuickBooks Online (QBO).
Based on your statement above, it seems that you're referring to the Service Date of the line item. If so, it refers to the date when the service was provided, and it is different from the invoice date, which is the date when your invoices are created or sent to your customers.
Since you want to generate your invoices first of each month, you'll only need to set up the interval correctly. See the screenshot below for an example:
Moreover, if you don't have specific service dates, then you can simply leave the field blank. You can also remove this from your invoice template by simply clicking the Gear icon and unchecking the box beside the Date in the Optional Columns.
For more information about the process, you can check this article: Create recurring transactions in QuickBooks Online.
Additionally, check out these articles that outline modifying the look of your invoices to match the branding of your company and record invoice payments to keep correct financial records:
I'm always around and ready to help if you have more questions about managing your recurring invoice transactions in QBO. Just click the Reply button to add your comment so I can assist you further. Have a great day ahead!