Newbie clothing question

I did well with a few pair of DeSoto tri shorts and a couple of their tri tops. I've never been a fan of the idea of a tri suit, and in my bike racing days always had fit issues with skinsuits. YMMV of course.

And just as an aside for swimming, for pool training, I found the best endurance out of polyester suits from Dolfin (though there are many brands of similar suits, examples below). I'd get at least twice the life out of these than I would any nylon/lycra suit. Save the tri shorts.

https://www.swimoutlet.com/p/tyr-durafast-elite-solid-jammer-swimsuit-42137/?color=9343

https://www.swimoutlet.com/p/dolfin-poly-solid-jammer-swimsuit-3345/?color=9748

What are you training in today?  

You need something you can swim-bike-run in.  For my first 2 tri's, that was a pair of swim trunks, add a t-shirt and running shoes after the swim.  

Try riding and running in what you swim in.  If it works, you don't *HAVE* to get anything else.  (Psst...try both while your swimsuit is wet too, it may be different).  

If you choose to get something else, get it early enough to train in it some.  One piece (trisuit) versus two piece (tri shorts and a top) is as much about personal preference as anything else.