Switching PC controls to mobile controls

I almost have a finished product, but I also want to make the game for mobile. When I switch the controls, will I also have to change anything in the C# code?

You will have to change the controls in the C# code to touch controls. This is not difficult to do and I would suggest keeping the non-mobile controls in as well just to be able to continue to test the game on the computer. You can remove them once you publish.