Looking for advice from the vets!

I went into my first triathlon with the swim being my weakest event by far.  I hadn't ever worn a wetsuit for swimming and had never swam in open water other than snorkeling/playing around.

I definitely underestimated what it would take to be successful on the swim, and ended up hanging from a kayak panting for life shortly after the swim start.  If you haven't yet, make sure to get in at least one open water swim in your wetsuit and all your planned race gear before race morning.

Not be so anxious....it's not that big of a deal

Have more fun and don't worry what other people are going to think...trust me, no one is paying attention to you.

This may come as a huge shock to your ego, but you need to realize that there will be 2,000 other people there who don't really care about you.  Some are going to be faster than you, some are going to be slower, and some may not even finish.  It's a race, not a fashion show.  Unless you are a professional, a bikini model, or the guy that keeps his helmet on running out of T2, no one is going to notice you.

Have fun!  Enjoy the experience.  Breathe, relax, and trust your training!

What would I have done differently?  Swim more.

Practice your transitions. Start with laying out your stuff, walk through the process, then build to where you're doing a full speed soaking wet dress rehearsal.

Worked transition in a duathlon this past weekend and saw a lot of fast-looking folks lose 3 to 5 minutes going from run to bike and vice versa. Also saw a few slower but better prepared folk pass up their competition in transition.

Nothing.  Go in as a complete green eyed newbie and take it all in.  You only get one of those, and then pretty soon you'll be an expert.  I remember the excitement before my first one, and I still get that same excitement at least one race a year.  I think the not knowing what's going to happen keeps you sharp

Have fun and enjoy it!

Outside of training more, I would have liked to spectate a race in person.  I think that will give you some insight as to what actually goes on in a race that we don't experience in training.  That should help calm some of your nerves.

^^this for me. The thrill of the sheer novelty of it all greatly outweighed the raggedy clothes, borrowed bike, and clumsy transitions. Have fun and do your best! But mainly, have fun

Relax for the swim start...that's the thing that gets most people the first time.  (Unless it's a pool swim with an individual--aka "time trial"--start, then never mind.)  Between the adrenaline rush of the starter's gun or horn (or cannon!) and 50 to 150 to 2000 people all surging into the water at the same time plus the unavoidable stresses of plunging into the open water, the stress level can be insane and it's really common to find yourself out of breath, even if you are well prepared.  (Happened to me at my first race and I had years of experience both swimming in open water and swimming competitively...still found myself a hypoxic mess at the first buoy and had to catch my breath and breaststroke for a few seconds.)

...That and practice your transitions, as others have said.

You've gotten a lot of great advice, from 'do nothing' to 'do this' and it's all worthwhile! So no matter WHAT you do or don't do ... if you go out there with the intent of having a blast, it will turn out that way.

(The one caveat as others have pointed out is to be prepared as possible if it's an open water swim--that, you really must do)

And for me, racing as novice (I figured, you only get one first race!) worked really well. But it just follows with much of the advice above - don't sweat the minor stuff (like whether you're in novice or age group), practice what you can (e.g. transitions), trust your training, and above all have fun!

You've got 46 more days until you race and you're this wound up? 

Why don't you go ahead and enter another race before the one you already entered......then you won't be so nervous when it comes around.

RELAX!  You are doing three things that you probably started doing shortly after you learned to walk.  Acting like triathlons are a big deal is a joke we play on people who don't do them....you'll have a blast!  And like others have said....nobody is going to be paying any attention to you except the people who come to cheer you on.

This might be the best advice I've ever read at BT.    

Seriously, get some open water swim practice and remember to have fun.  You'll have a great time.