If I know c# then learning python will be easy?
It depends, if you understand the basics of programming then it should be easy. The only difficulty could be learning python specific concepts. SoloLearn has a Python course give it a try.
It certainly doesn't make difficult . Well Object Oriented Programming concepts will help you learn any other object oriented languages-basic concepts. Main aspects of OOP like inheritance ,abstraction,polymorphism,encapsulation are present in all OOP languages..using basic statements and loops will also be easier.The statements and loop formats may be different but overall you get the general idea; I mean logic of statements,loops and OOP concepts.