Try to strenghten your thigs muscles. I also used to weak at long pass & long shot, but after train my thigs muscles I'm bit better at taking long shots. And my shot power also increase. Try exercise like squat jump.
My goal kicks only go about 40 yards, but I want to be able to kick the ball about 60 yards or more in a few months. I know that I should go out and practice actually kicking the ball, but are there any exercises that I can do to strengthen the muscles used in kicking the ball, or that will improve my kick?