What we are using for the Demo Page !!
We are using free WordPress theme called Astra. You can search it in Theme directory or directly from admin by going to Appearance > Themes > Add New and Search “Astra”.
Here is the link to the theme,
This theme pretty awesome and comes handy with lot of premium features in Free Version. Once installed you have option to import a number of prebuilt demos which are almost ready to use.
We are using one of such demo called as “Italia Restaurant” under the category Gutenberg. Here is the link for the demo website.
After the setup of demo site is done, we went for WooCommerce setup and created “Order Online” page to place our shortcode. Hope this helps you if you want to prepare similar design.