Ok, well, if you have no experience with coding and you're using an Arduino for this, then you have chosen something that is certainly not a simple way. I see three feasible options:
1: Use the Arduino, but learn to code as you'll be stuck at every corner otherwise.
2: Get someone else to write the code for you. Maybe someone wants to spend their time on this (most people expect payment though).
3: Buy a ready-made solution.
If it's just to get a button box for a simulator and you have no real interest in embedded systems or Arduinos, I would suggest option 3. It's by far the easiest and smartest solution. Option 1 is a lot of fun, but it's going to cost a lot of time. Option 2 is putting yourself at the mercy of others and it's probably going to cost time and effort to persuade people and you may or may not be happy with the end result.