In order to look up an order and cancel the order in Spark, you will need to go to the Purchases Report.
Sales > Purchases > Purchases Report
In the right hand corner of the page, search for the customer's name, email address, or order number to find their order. Be sure that the correct date range has been selected on the left side of the page.
To cancel an order, hover over the order number and select "Cancel". That will send your customer a refund and confirmation email of the cancellation in 2-3 business days.