Hi Harri,
It seems to me that you are struggling with the concept of dealing with JSON.
Have a look at this project that I created using your json file (slightly modified and named meals.json), your structs for decoding the json (although slightly modified and named Meals.swift), your decoding code (again slightly modified so that it is wrapped in an extension on Bundle and named Bundle-Decodable.swift) and a ContentView.swift file to present the data on screen.
Download the project and double click on the file to unzip it. Open the folder RestaurantMeals and double click on the file RestaurantMeals.xcodeproj to open the project in Xcode.
Hope that helps.