Unfortunately, Shopify doesn't make it too easy to find the fees reporting. The simpliest way is to do the following.
Step 1:
Go to the "Orders" area in Shopify backend and then click "Export" button in the top right
Step 2:
Open the file you just downloaded in excel or google sheets. You will now be able to sort or filter for just the fees (column R) and gather the totals (column S).
