Hi there,
You've reached the right place for help. Displaying tax on your invoices is important and I'd be happy to show you how to do that.
Have you set up sales tax yet? If not, I encourage you to check out the following article from our Community:
https://quickbooks.intuit.com/community/Sales-tax/How-to-set-up-a-new-sales-tax-code/m-p/261929
The article will show you how to set up a sales tax code in QuickBooks. If you've got questions, feel free to reach back to me. I'll be happy to help. :)