1.
https://www.bikeforums.net/training-nutrition/
2. Each person has different goals for riding a bicycle
3. Based on those goals, it's the aggregate of TIME and INTENSITY. Miles are like asking "how long is a piece of string".
Lastly, there's a lot of questions like this that boil down to people wanting some kind of answer to something not knowable without knowing their goals. I know a LOT of recreational riders that pour in 200+ "miles" a week just sucking wheel for hours at a time. Absolutely nothing wrong with that. But they always ask "why am I still slow" or some other variant of that complaint. Well, you ride for enjoyment. Do you want a different goal? Why not have enjoyment be the goal instead of something else if you don't need to?
If your goal isn't a specific racing discipline, we're making the topic more complicated than it needs to be.