Is it normal to not know how to ride a bike?
Yep.Totally normal
Yes, it’s normal not to know how to ride a bike. Plenty of people never learned, and you can learn as an adult if you want to.
Absolutely. Maybe you didn’t have a chance to learn as a kid, didn’t have a bike around, or just never needed one. It’s a useful skill for some people, but it’s not a requirement for being a functional adult.