can walking on a smooth surface or polished surface be easier???

Your friend @Shubha18 is correct. Keep it up. 

No , walking on polished surface is not easy as the friction force will be less if the surface is polished. The body may tend to slip while walking on a polished surface.see the figure below:

Frictional force is a contact force which comes into play when the surfaces are in contact with each other. For the irregular surface, the frictional force will be more when the foot of the person walking and the surface are in contact. On the other hand, for polished surfaces, the frictional force will be less.

However I would like to mention an important point here , if the surface is excessively polished, it may result in increase of frictional forces as at atomic level, molecular bonds are formed between the contact surfaces. A greater force will be required to break these molecular bonds resulting in increase in friction