Let's apply the first step to CH4.
The electronegativity of Carbon is 2.55
The electronegativity of Hydrogen is 2.20
Electronegativity difference between C and H = 2.55-2.20= 0.35
(The electronegativity difference ranging from 0.0 - 0.5 is considered to be negligible. Thus, non-polar.)
Conclusion: CH4 is a non-polar molecular, due to negligible electronegativity difference which means no dipoles(partially positive & partially negative) are created on the molecule, keeping the molecule to be non-polar.