Hello,
Please follow this article to set up addons for your food items.
http://food-store.wpscripts.in/knowledge-base/setting-up-add-ons-for-your-food-items/
Regarding your layout, we are guessing you are using some kind of page builder where the shortcode is not placed properly. Please make sure to place the shortcode in code view of editor not in visual editor and please make sure there are no HTML tags around it as wrapper.
Thanks & Regards,
Team WP Scripts
Yes the shortcode is in the correct view and has no HTML around it but the format still looks incorrect when compared to you demo:
http://staging2.themoondropcafe.com/test-menu/
Hello,
Food Store is designed to make it look like your theme, so whatever stylesheet we are using for the layout, if your theme is overwriting those stylesheet for example image size, or heading font size they those stylesheet will be applied.
I suggest you to test the plugin with Storefront theme once, if everything comes fine then clearly your theme is changing the stylesheets for major elements of Food Store.
Regards,
Team WP Scripts