Native english speakers would comfortably understand both, but I think what sounds more natural is the following:
The school's only ten minutes away, so I don't take the bus.
It's only a ten minute walk to school, so I don't take the bus.
It only takes ten minutes to walk to school so I don't take the bus.
I don't take the bus because/as it's only a ten minute walk away.
Any of these are fine. Saying never is technically okay too, but using the word never is very definite and negative. It's more natural to say don't or to say "It's only a ten minute walk away so there's no need to take the bus".
Hope that helped!