When a guest accesses your menus through the QR code, they will be able to see each of the menus that you have uploaded. To change the order they appear in, follow these 2 steps:
1) Log in to the dashboard and select Menus
2) Use the arrows on the right to change the position on the landing page.
Menus will be displayed in the same order they appear on the dashboard - the top menu on the dashboard will be the leftmost menu on the landing page.
This is a live change, so your menus will instantly be shown in the new order on the dashboard.