Where can I find it?
To find it, first hover over the "Earn" tab at the top of the application, and then select "Summary".
Once you've entered the Summary page, your pantry will be shown at the bottom of the screen.
What do these badges do?
The Pantry stores all the Veggie Badges that you've earned for your Salad XP. The longer you run Salad, the more XP you accrue and the more Veggie Badges you'll unlock. These are little more than marks of pride, and marks your progress as you use the app. You can read about XP related rewards here.