What to wear for my first sprint triathlon this saurday

Ruth,

Exciting times!  Have you tried running in your swimsuit?  If not, that should be the first step (hah...I'm funny... ).  If the swimsuit/bra is OK to run in (you can pull a pair of shorts & t-shirt on over the swimsuit if you want), that can easily be your backup in case the tri-suit doesn't show up as planned or doesn't fit like you need.  If the tri-suit shows up, do the same thing, try running in it.  Race-day is not the day to experiment. 

At the race, you won't usually have a place to change, so you should come wearing your tri-suit/swim suit and expect to keep it on until after you finish.  I bring a change of clothes for the ride home and can usually find somewhere to do so (lines won't be as long after the race, so you can potentially use a port-o-pot for changing afterwards.  Public nudity may be appreciated by some spectators, but is frowned on by others, and more importantly the race officials (you can be DQ'ed). 

You have somehow managed to tie shoes before running (or riding) up until this week.  Elastic laces (Yanks) can make you faster transitioning from one to another, but aren't necessary.  If you don't have a race belt, pin your numbers to an oversize t-shirt (make sure you only pin through the front, not both sides of the shirt).  You can pull the shirt on after the bike (so it isn't flapping around on the bike).  Make sure it's big, because it'll be hard to pull on a sweaty body when you're really REALLY excited and out of breath.  Alternatively, find a scrap of elastic 3' long and pin the race number to the elastic.  Tie it around your waist after the bike (unless you need the number while on the bike).  It won't be quite as nice as a race belt, but you don't need to buy anything more to do your first race.