To view payments to your nonprofit's payment account, go to the payment account page. You can get to this through clicking Profile, then Payment Accounts towards the bottom of the page, or by going to https://www.givesignup.org/PaymentAccts and clicking Manage.
Next, click the tab for Payments.
Click View Payments and select the dates you want to filter by to view a list of payments in that time range.
You'll see a table with the links to the details of that payment, the date, status, any notes, and an amount.
Clicking into a payment will give you more details on that payment. You can drill into specific numbers using the reports icons: