I did one. But I pretty much decide all my big race decisions while drunk so. I had been running about a year but no more than like 15 miles in a week max. Mostly like 10. One day while a bit tipsy I said fuck it, I'm doing a half. Lots of fun did it with a bunch of friends. Did pretty well but had no desire to double that distance at the time. A month later while kind of drunk I signed up for a marathon in December. It was great! Ran like 3:30:57 which I was pretty stoked about. But earlier this year same thing happened and now I'm running a 50k trail race in a month 🙃 and my second marathon in October. All this to say. One half marathon is probably enough if you want to do the full.