Welcome! Triathlon is more addictive than crack (and way more expensive)
You will find that there are lots and lots of things that you can do to your bike. At this point, I probably wouldn't worry too much about your crank and training wheels unless your race is within the next few weeks (what crank & wheels are currently in the bike)?
Aerobars are a maybe depending on how your bike fits you. The clip-on approach is probably correct but you still may find yourself too stretched out with them so they might call for a shorter stem or forward seat post (see what I mean).
Good luck with your training and racing!!!