“There’s no harm in (doing something)”
– doing this will not cause problems and may even have a good result
A: I’m a woman so I am shy to ask him out for dinner. He might think I’m an easy girl.
B: Come on, there’s no harm in asking.
A: I wish I could play the piano as good as you! Do you think I should start learning now?
B: Of course! There’s no harm in trying anyway.