Thanks for joining us here in the Community, @karynmurphy.
For your two concerns, you can run the Bills and Applied Payments report to get the year-to-date data for your total vendor check stubs. I'd be glad to show you how:
Go to the Reports menu at the left pane.
Enter and search for the Bill and Applied Payments (Bill stub, Vendor check stub) report.
Choose This Year to Date as the Report period then choose a date range. This is to refresh the data and get the desired report.
Also, for your first concern about vendor attachments, you're able to access and view it once you open the transaction in this report. Here is an article on how to add a vendor attachment: How Do I add an attachment for my vendors in QBO?
Moreover, you're able to customize this report if you want to see more details aside from the ones you mentioned. Please refer to this article to know how to do it: How to customize reports in QuickBooks Online.