Human bodies are not precision machines and it is common to have slight differences in leg length. Having a longer crank one side is not going to help because this will make the one leg go higher at the top of the pedal stoke.

Unless the difference is so extreme that you need a build-up shoe on one foot to walk normally, (In which case you may need a build up cycling shoe.) don’t even worry about it. At the bottom of each pedal stroke on the short side your toe will point down a little further than the other side.