At this stage in the game it doesn't really matter. You need to concentrate on learning to swim and the other stuff will come later.

I didn't get a pair of tri shorts until this year - my second season. I trained most of last year in a regular pair of swim trunks then got a pair of long speedo's. Did I notice a difference? Not really. My swim stroke has changed a lot from when I started and I really atribute the increased speed and decreased time to better technique.

So, for now I would focus on learning some drills and getting your endourance up.