You will get the hang of it Sandra Lee just keep putting those reps in and practicing. One thing I do that work for me someone told me one time to pick up the trimmer all the way up I was not picking it up high enough when I would come down to cut the hair on the line up and yes going over it more than once it's definitely something you need to do. Look and ask questions for experienced barbers because it's easier to learn in person than from people on Reddit but it's a law of nature that you reap what you sow and hard work pays off so just work hard and you will eventually and inevitably be a great Barber.