I thought that starting out as a developer at 42 was a bit too old. I felt much better when the new guy I started with admitted he was going to be 50 at the end of the month.
I am 37, studying web development (mostly Javascript) for 4 months now. I feel I learned a lot of the language itself, but I'm struggling with other important components of being a good developer, like proper use of git, comments, tests, etc.
http://web.mit.edu/6.031/www/sp17/classes/05-version-control...
http://web.mit.edu/6.031/www/sp17/classes/03-testing/
https://stellar.mit.edu/S/course/6/fa16/6.170/materials.html
https://www.udacity.com/course/how-to-use-git-and-github--ud...