It is fine if you don't know. It's good for your heart if you try to keep your heart rate up for at least half an hour a few times a week. Don't push yourself too hard, the duration is more important than the intensity. If you do that consistently, you should find that your stamina improves with time.

[Everything laid out, Zelda starts pinning her hair into a bun at the nape of her neck. No one wants cookies with hair in them, after all.]