I do not disagree with what the previous posters have said.
I offer this bit of advice. Go to as many triathlons as possible within 100 kilometers of your town, if only as a spectator if you're not willing to just give it a go on whatever you currently ride. Sprint triathlons are fine, as you need not focus on half IronMan 70.3 competitions. Yes, sprint triathlons (~22 miles or so on the bike) will have first time novices and first timers riding ordinary bikes and first timers riding race bikes who can't keep up with the 40 year old on the 50 year old Raleigh Grand Prix 10 speed. You get normal people like that that are first timers or doing it to have a blast, but you also always have a dedicated core group of super-serious tri folks that do it to record times in a sanctioned event, and they just love competing so much and if that week's scheduled event does not conflict with some bigger event, the serious tri folks do show up in numbers, especially when such an ordinary Sprint tri is just the week prior to a major triathlon event as it works as competitive training for the following week.
If you're just a spectator and you want to pick the brains of the participants. Do not bother the participants with questions before the event starts. You will not be allowed into the Transition Area where the participants bikes are staged. THE BEST TIME TO TALK WITH PARTICIPANTS AND THEIR EQUIPMENT IS AFTER THEY COMPLETE THE TRIATHLON , WHILE THEY ARE LOADING THEIR VEHICLES....or anytime after the event, But Not During The Awards Presentation Ceremony because though they would love to talk with you about what equipment and such, they do treasure and respect the awards presentation, so that time is not right, as that is sacred time to give the respect and congrats to fellow competitors. You will find that for the most part that serious tri-competitors are probably the nicest, easily approachable, gregarious, good-will ambassadors for their sport, who will gladly speak freely to you about what, how and why they choose particular equipment. They also tend to be the most optimistic and encouraging people that you will find anywhere. That is based on my more than two decades experience with such events all over the United States.
Sure, some folks might not want to talk more than 30 seconds for whatever reason, but I guarantee that you'll get someone who wants to tell you everything and will continue talking and showing you their bike(s) for nearly a half hour. I do suggest that if you go to an event as a spectator, that you capture some video with your phone or a high quality HD camcorder. Offer to give the video to the participant(s) that you speak with, and also place it on youtube for others to see, as well as any site links/forums that discuss said event.
This is just a suggestion that I think will give you more insight and credible information than you might ordinarily find. Be cognizant that these folks are being kind and are certainly doing you a favor by telling you everything, but you'll find that they do love their sport and they really love to talk about it, especially after completing a successful and satisfactory triathlon, while drinking a cold beverage and being with friends, family, fellow competitors, officials, and event spectators. Be kind and considerate and do not monopolize all of their time.