Let's say I have an idea for an app but have no money to hire a programmer and zero knowledge of coding. How realistic is it to learn it autodidactically vie free or cheap internet resources and develop a viable product? How long would it approximately take me to reach a level sufficient for this? Is a CS degree necessary at all? Are there any resources for learning you could recommend? Any common mistakes to avoid?

Some facts about myself that might help you answer my questions:
>25yo
>reasonably intelligent but no genius by any means (~125IQ)
>no experience with maths and general aversion, but alright understanding once I'm forced to learn it
>poorfag, so can't afford expensive online courses