What’s a practical amount of meals I should be making in a week?

My wife and I are trying to cheaper and healthier so we want to try meal prep. I am wondering how many I should start out making for the week. If we did lunch and dinner for my wife and I 5 days a week that’d be 20 meals. That seems like a lot to make and I don’t know if we’d have room in the fridge/freezer. What’s practical here?