I'm closing in on 40 and trying to run my first sub 4 hour marathon before then. I figure you don't really start running that fast after 40, so this is my last chance to ever be a 4 hour marathoner.
Males have to get to 65 years old before a 4-hour marathon will even qualify them for Boston.
I'd wanted to qualify for Boston in my 20s, which at the time required a 3:10 marathon. It was just barely at the limit of possibility, if I had a perfect day, which I never did.
Then they dropped that limit to 3:05, and that might as well be on the far side of the moon. So, I never run Boston. Ah, well. That was a very stretchy stretch goal.
You have plenty of time, I've trained with lots of people that started late and were still running impressive times.