Welcome Newbie! We were all new once and now we are all addicts. You will have a load of fun on that 16. The 16 is one of the best boats ever built and has such a strong fleet. Parts can be found everywhere.
For your list of needs, you are correct on the items you listed. Get comfortable life vests that allow free movement of your arms like kayakers use and make sure they are Coast Guard approved. The cheap ones at Wal-Mart are just that, cheap and rub in all the wrong places.
Add trap harness(s) to the list. They come in all sizes and shapes (and prices). Each person has a reason they like theirs, so much so we could fill this forum about it. As a skipper, I like a short "diaper" with my crew having a full over the shoulder harness. The type of connection to your trap wires will be key as there are a few different types out there. The simple hook is the most prevelent and probably what your boat has. Check out Murrays Marine (http://www.murrays.com/
) or your local Hobie/Cat dealer to see what they have. It is always best to see them in person.
Sailing gloves will save your hands and are also a must. Murrays/West Marine or your local sailing center should have a few different ones to choose from.
I am a cold water sailor so I also have a wet suit, spray top, booties, and a hat. The hat goes everywhere with me for protection from the sun. Speaking of sun, don't forget your sun block, get it water proof.
On the 16 I don't wear knees pads but I sure do on the 17, but many sailors do use them on the 16.
I like a little parts bag that I can connect to the tramp to hold extra drain plugs, rudder pins, a couple beers, and extra pins with rings. Cuz things happen.
The list can go on so the best thing you can do is go sailing then go to a Hobie regatta and talk up the other sailors as they will gladly help you.
No license required to have this much fun. Ah, the Hobie life is grand.