Arriving at the Venue
Plan to arrive at the venue early, at least ninety minutes before the start of the race. Two hours would be even better.
There is a lot to do at the site of the race, including finding a place to park. The later you arrive, the farther you will have to trek with your bicycle and other gear, not to mention the effort to haul it back to your vehicle afterward. You won't enjoy that a lot when you are sweaty, hot, and tired from the exertion of the race, not to mention full of food and drink from the pos-trace feed.
Here is a list of things you will have to do after you find a parking place:
Have your race number written in waterproof marker on your arms and legs. It's mandatory for everyone so that race officials can identify competitors. This can mean long lines and lots of waiting. By the way, the numbers disappear in a few days with normal bathing (or you can wash around them to retain proof that you are a triathlete for as long as possible).
Find your transition spot. The earlier you arrive, the better spot you will find for racking your bicycle and laying out your other gear.
Pin your race number to your bicycle and possibly also to your helmet.
Hit the port-a-john line at least once.
Triathlon organizers are very strict about littering. In some races, disqualification is the penalty for that offense. If you carry a gel on your bicycle or during your run, be sure you have a place to put the empty packet.
Those are the certainties. You might also have to pick up your packet on race day, and you might need time to apply sunscreen and to oil your bike chain. There is a lot to do.
Getting Warmer
And, of course, you will have to do all of these aforementioned things before you warm up. All in all, it's much better to hurry up and wait. You will have time to check that everything is where it should be and socialize with your friends. You will be able to hydrate and fuel adequately and at leisure.
If you are tense at the start of the race because you had to rush through everything, it will affect your performance and enjoyment of the event. Do whatever is necessary to get to the race site well ahead of time.
