Advice for getting started

Is it crazy to start with a half Ironman?

I (22f) just graduated college and started working full time. I am wrapping up training for a marathon in mid-October looking for my next challenge. I have really enjoyed the structure of training for a big challenge and have started thinking about getting into triathlons next. I do a good amount of running( very slowly-marathon takes me about 5 hours), own a peloton and do lots of spinning but don’t have a road bike (yet), and have nearly no swimming experience at this point. The idea of having a lofty goal like a 70.3, to work towards for an entire year excites me. Getting up early to fit in workouts helps me feel productive and keep me from getting bored as I get used to my new schedule. I keep trying to tell myself that I likely don’t understand what if would take to train for a half Ironman, and I don’t know enough about triathlons, but I can’t stop thinking about it. I know starting with Olympic distance would be smart but since I live in chicago, I sort of missed the season and I don’t feel like I can train for a whole year for an Olympic triathlon. I could do a few at the start and then do a half Ironman in the early fall. Does this sound insane or would it be possible if I really dedicate myself to training for a year?

Does anyone have any advice? (Major concern is cost-where should I invest? Get a coach? Bike fitting? Gear?)