I'm in my late 30's and I'm a junior dev, having been in the role for just over a year. If you are persistent you can do it. From my experience it has been a hard and at times frustrating job simply because there is so much I don't know, but that comes with the reward of the eureka moment, where when something works it is one of the best feelings.

Now in terms of doing a school, if it's a scheme where you pay for the training and they say they'll get you a job at the end, please be cautious. I have a few friends that went down this route and they say they were the lucky ones to land jobs, but in their groups everyone else was left out in the cold at the end.

This was just my process but I did the Java MOOC course that taught me enough to get going, I was doing this at the same time as working in IT. It's completely free. For frontend learning I've been using Scrimba which has free content but also a paid for subscription, it has been alright and the way they merge the recordings with the IDE is good and the free content feels more substantial than what you'd get with Codecademy.

I'm still just a noob at all of this, and there is so much I don't know but I'm happy to try and answer any questions you have.