I would like to compete in my first triathlon this summer. I am very clueless on how it all works. First of all, I own a cheap mountain bike, will this do for the bike section or am I going to get laughed at on my huffy? Second, do you have to wear a wet suit and if not and don’t own one do you just wear a bathing suit? When in transition after the swim do you put other clothes on? How do you find your bike? I just don’t know all the little things and if someone could help me out or point me in the right direction for a beginner I would appreciate it so very much. I don’t want to go pro I just love challenging myself. I’ve done a marathon and now I want to try something new. All the websites I’ve gone to don’t offer answers on the little things and I’ve never seen one so like I said, I’m very clueless.

You need to link up with live people and ask questions. I suggest this website:
http://www.beginnertriathlete.com/

You don’t need to buy a new bike — at least not right away. No, a mountain bike is not ideal, but it will do fine for your first race — especially if it is 15 miles or less of biking. I live in one on the top-3 triathlon meccas in the US, and beginners here sometimes show up with mountain bikes. People will know that you are a beginner — but so what? Everyone has to start somewhere, and I’m sure everyone can relate to the nervousness of the first race. Upgrading your tri equipment can become a major expense, so figure out if you like the sport before you start investing.

You don’t have to wear a wetsuit, but if you are swimming in water colder than 75 degrees or so, you’ll probably want one. If you can’t find a store that rents them locally (the preferred route, because then you can try it on), you can rent one online.

You will keep your equipment for the race in a cordoned-off area called "transition." (The race organizers provide security around this area because of all the $$$.) Depending on the race, you may be assigned to set up in a specific area, or even a specific spot. Before the race starts, you set up your bike and your running shoes there. After the swim, you run to this spot to get your bike. After the bike, you’ll go back to this same spot to rack your bike and start your run. Transitions between sports are another component of the race, and should to be planned and rehearsed in advance.

There’s a lot to learn. If you can, find someone to talk to — and ideally train with. If there are no stores in your area that appear to cater to triathlon, go to a specialty running shop and ask around. They will be able to help you select essential triathlon gear. You can also check out a Masters swimming group, because there are often triathletes training with them:
http://www.usms.org/placswim/

Good luck! It can be quite a journey.