Learning to fly
Don't go nuts buying every pilot gadget you see. You'll find that simpler is better and less is more. Your private pilot kit sounds about right, along with a regular clipboard that you can find in Office Depot or maybe your neighborhood grocery or drug store.
You do need a flight computer. All you
really need is a good, old-fashioned aluminum E6-B and a five-buck (or less) electronic calculator. Try to find a light-powered calculator. Your calculations will consist primarily of basic arithmetic, e.g., addition, subtraction, mutliplication and division.
I assume your trainer is intercom-equipped. So, sometime, you will want to purchase your own headsets. You can spend a ton of money on headsets and end up with something you hate. Shop carefully. Try them before you buy, if you can. By all means, don't buy them at retail from Sporty's. Purchase your headsets by mail order from some outfit like Chief Aircraft Parts,
http://www.chiefaircraft.com , (that's where I bought my David Clarks fifteen years ago) or Marv Golden,
http://marvgolden.com .
Really, your flight instructor can give you the best advice on "stuff" to buy.
Flying three times a week is about right, if you can maintain that schedule. Not only are you receiving a whole lot of book learning, you are educating your muscles and senses. Your mind needs some time to absorb the learning. Some people advocate a real fire-hose approach of flying seven days a week, sometimes a couple of times a day. That's a great deal of learning to try to absorb in a short time. You could find yourself falling behind if you cannot master each lesson's learning. Learning to fly is like building a building; the foundation has to be poured and laid properly or else it will be weak, and the structure that is built upon it will be weak.
Do get your medical ASAP, as the others suggested. You'll need it to solo and you want to find out sooner instead of later if your health will permit you to fly.
I remember that I had trouble with landings and S-turns down a road. I was not really good at the ground reference maneuvers until I became a flight instructor and had to teach them. Then, they became some of my favorite things to fly and teach.
Good luck and have fun with your training.