A water bottle is really useful but before you step foot on the course, you should really work at the range. I would suggest you start with your short irons and only hit every other one. So maybe 6 iron, 8 iron and pitching wedge. Then work on your driver and fairway wood off of the ground. When you begin, there's no real reason to carry a full set of clubs. I also recommend carrying every other club because you probably won't be able to tell much difference between your 7 and 8 iron on a consistent basis.