Feel like going for a run?

I've decided to train for a marathon.  Not necessarily run one (TC marathon registration is closed anyway), but train for one. You might be thinking (or at least it's always my thought): isn't that what comes at the end of an Ironman? I love the shirt that says: You ran a marathon, aw, that's so cute.
I'm training mostly out of boredom. I've found working from home leads to being a bit of a shut in. To get out and at least see the outdoor world, I go running most days. It seemed only natural to train for a marathon, since I regularly run 10-15k many days.
My triathlon training has been in a downward slide for the last year and a half as the chronic pain in my back has gotten worse Biking long distances aggravate the pain, but distance running has little effect.

I've been searching for a race that would be good for my first marathon. I was tempted to do the Vegas marathon, but that has a time limit of 4.5 hours, something I could probably do, but I don't want to chance a DNF. Luckily there is a half marathon option for Vegas, so Angi and I might do that. Kaleb is finding all the Japanese marathons, so he would have an excuse to go to Japan again. I know it's not necessarily normal to train for a marathon when you don't have a marathon to run, but I'm having fun with it for now.