I frequently see the question, "What do I wear for my triathlon?"
You can find many different solutions online. Search the forum at iamtri.com or beginnnertriathlete.com and you can find this question has been answered over and over again.
Personally, I'm a big fan of the two-piece tri suit. I have three. I train in them religiously and I have my favorite. One of them even matches my bike.
But I've learned several things about what to wear, and what not to wear during endurance sports.
First, the baggier your clothing is, the more likely you are to chafe. Coming from a running background, I have all the cute running skorts. Guess what. I used to bathe in body glide to keep from chafing so badly that I'd walk bowlegged for a few days. I once saw a guy during the Austin Marathon bleeding from his nipples from chafing so badly. No more cute running clothes...
Second, everyone wears tight fitting lycra, and no one cares!!! If you catch a stranger looking at you, they're probably admiring your tri suit or jersey, and wondering what brand it is. In one race, I saw athletes with their names on their bottoms. Try not to stare at that!
Third, train in it. If you wear your pretty new tri suit the day of the race, you won't know where the hot spots are. I have one tri suit that I have to coat the inner seams so I don't chafe or blister. I'm glad to have found this out before race day!
Unless you're doing an Iron distance event, the likelihood is that you won't have a changing tent-meaning you won't get to change. Tri suits reduce the time spent in transition and give you one (or more) fewer thing(s) to worry about.
Since I started doing triathlon, my running gear has gotten a makeover. I now run in either a tri suit, or compression shorts and a racerback top.
The most important thing to remember is that no two bodies are alike. What fits one person just right and doesn't chafe may be too harsh on another person's shape. One brand may work well for one person, but not at all for another. Be prepared to try different things.