If i'm 24 years old, can you develop asthma out of nowhere?

Yes: You can definitely develop asthma as an adult. A doctor will help you address trigger factors and help you form a management plan.

Yes: Though it is most likely to start in childhood, asthma can occur at any age. Things that alter your immune system like pregnancy, severe illness, or stress can cause asthma to develop even if you've never had it before. Also, if you have had allergies your whole life these can eventually lead to asthma as well.