Should I learn UI Design first or learn to code first?

Hello there,

Anyone can please help me on this question?
Should I learn to develop the content of the game before? Includes storylines and character … etc
Or is it a priority to develop programming skills first?
I have some basic skills with C#, Python.
I have made few 3D games worked by using Unity3D.
Because game industry in my country is not good. So I need help. I appreciate the self-learning.

Thank you

Programming. It doesn’t matter how much you know about content of your game if you can’t implement it.