Hi PattyF,
For billings/costs within the job, you can make it billable to it so you can create an invoice out of it. On the other hand, for invoices outside the job, select the customer name as the payee instead of the job name.
If you like to know more about billable cost, you can press F1 to lunch the Help window and search for billable cost.
You can always visit us here if you have other questions.