Welcome to the internet, you can find some there. If you want a shop, Google swim shops in your area. I highly recommend a master swim coach, you can Google that too. And as far as etiquette, circle swim. If you can, don't jump in a lane with someone who is clearly much much faster than you, if this is unavoidable, try the lane with the fewest people. The whole point of pools is to learn and perfect swimming, I have been swimming since I was 4 years old (18 now) and I am still trying to perfect my technique. Unless you are actually 5 feet across, which i assume you are not, since you are physically able to try a triathlon, you will not be in the way.