Hey Lisa, good to see you here too.
With swimming you need to get good help right off the bat. Just jumping in and going will only make you produce bad habits that are hard to break later.
Find a local tri club or a masters swim group and get it right from the start. As for your first tri, your perfect swim stroke most likely wont be there anyways. There is so much going on that it's hard to relax and get it right the first few times.