Before I started C25K I did quite a bit of walking in the hope it would increase my fitness. Being able to walk for at least 30 minutes is a good indicator that you're ready to start C25K. But which is better for you, walking or running?
This is an interesting article from the New York Times which gave me some insight into this very important question.
nytimes.com/2023/11/14/well...
I don't think it's behind a paywall, I believe that the NYT allows you to read a certain number of articles each month for free.
Happy reading, happy walking and happy running all!