Hi rwaqawas,

It's great to hear that you're interested in using the Canadian version of QuickBooks Online for your business needs. To discount line items, you'd need to create a product/service called discount and input it as a negative amount. The steps are listed in this article: Apply a Discount to a Single Item. You can also add service charges in the method in the article.

If you have any questions, please let me know. Take Care.