Be warned, Be careful
Generally speaking, Ironman Triathlon and the people who "follow it" are...... different. In a bad way. I know, I used to be one. Try something else rather than Ironman, you'll thank me later.
And to the guy who said that he couldn't swim. Don't let that worry you. The closest that I came to swimming before Triathlon was nearly drowning twice. I taught myself how to swim by reading books and via YouTube. Swim Smooth is your friend. It took me 12 months to get up to swimming 4km "comfortably" through persistent effort.
I enjoyed Triathlon, just the Ironman groupies were a bit "Yukky".
I am looking forward to getting some time in the saddle on a MTB. It seems to be more low key.