Invoice Customization for Service Oriented

I am a service provider and do not need Quantity and Rate Column. Neither do I possess any expertise in programming language. Please let columns and rows be editable. Not able to use the software right now.
If there is any such option already there , then please inform.

The invoice will not show Qty and Unit Price column if you don’t enter anything into Qty column. So make sure qty column is empty of each line item. Manager will figure out you are not using it and won’t show it on printed invoice.