Journey to nowhere vs isolation zone

I am playing on the latest android version but this is more a general card question so I didn't post it in the Android thread.
I have both isolation zone and journey to nowhere in my deck. Isolation zone will not let me target a planeswalker but journey to nowhere will. Both say creature so I am confused. Should both be able to target planeswalkers or should neither.
I am likely just miss understanding how something works so if one of the rules guru's could help me out that would be awesome.
I have both isolation zone and journey to nowhere in my deck. Isolation zone will not let me target a planeswalker but journey to nowhere will. Both say creature so I am confused. Should both be able to target planeswalkers or should neither.
I am likely just miss understanding how something works so if one of the rules guru's could help me out that would be awesome.