How do I just view the unread submissions?

You can view the form submissions in the View Submission page.

user guide: -How-to-view-Submissions

To identify the number of unread submissions, you can see it in the My Forms page with the number highlighted in red. 

And in the submission view grid, you can identify the non opened/read submission using the close envelope icon inthe 'New' column of the grid

There is no option to filter read vs unread submission though. You can only identify them instead.

Hope this help. Let us know if you need further assistance.