Differing suits might provide a benefit, but I think that would be offset by your overall skill level.
Older swimsuits and skins increased the amount of drag on the body, which is a bad thing for competitive swimming. I noticed a big difference in drag between the speedos I wore during Masters swimming versus the light skin I wore when scuba diving. The rule then was less is more as your own skin presented less drag. << Insert obligatory "yes, I dated myself there" comment >>
Newer swimsuits / skins can present less drag than your own skin does since the material is a tighter weave. Case in point, many Olympic swimmers are now wearing full swim skins. I believe the balance now is between economics versus performance gain.
I think I would purchase suits based upon the temperature of the water you expect to be competing in. If it's a lake and you know it will be cold, having a little heavier suit will keep you warmer so you can function better. Likewise, if it will be more reasonable temperatures then I would go with a lighter suit. The focus is really upon staying warm enough that you can keep swimming.
I don't compete in triathlons, but I expect you wear the same base layer for all 3 events, so keep the other 2 events in mind when picking your swimming gear.
Finally, I would recommend just focusing on improving your overall swimming skill versus worrying about the minimal benefit that you may receive from aerodynamics. After you get to the point where you're knocking out a few miles of swimming per practice then you'll be at a point to consider differing suit types.