You know already that I’ve only done two triathlons. Jersey Girl and Iron Girl. Each was considered a sprint triathlon but the only consistent thing about them was a 5K run. Jersey Girl was supposed to have a 300 yd. swim (it turned out to be shorter due to the weather) and an 11 mile bike ride. Iron Girl was a 1/3 mile (540ish yards), 15 mile bike ride and a 5K.  Starts can be from the shore on in deep water for the swim portion. There can be other variations that may affect performance that you should be aware of.

Even with races that are Ironman and Half Ironman, you need to know the rules. Knowing the distance is generally not enough for you to be successful. Is there a long walk from parking to transition? How early do they open?

You get my points. There is enough to deal with on event day without being blindsided by something you could have handled earlier. Just my thoughts!