Hi for it mate, you won't regret it. I ran the Manchester Marathon in 2021, aged 60. If I hadn't done it then, I probably wouldn't ever have done one, based on my injury record of late.17 miles is about the furthest I've ever run. Bizarrely it was on one of the Garmin half marathon coach plans. Don't know whether it was supposed to be kms instead of miles and hadn't been converted correctly or what.
Sort of hit a wall about 15 miles which is odd as I can pretty much do a half marathon without any training by taking it steady. Bought a Camelpak after that but never done that kind of distance again.
The thought of a full marathon makes me feel sick. Especially lugging a 85kg frame about. Be nice to say I've done one though and have it ticked off.