Medium is easier to start out with... heavy wall is easiest to control, but you'll need to blow it out thinner for the applications you're attempting, so Medium is a good compromise... it's thin enough to do inside out beads, ornaments and what not... but not so thin that it collapses with a little bit of heat... tubing is fun, but frustrating... just keep at it... it'll get your mind and hands working together with some practice.
