S.H.
Non-profits, REALLY vary.
I've worked for non-profits.
Some are good and organized and operate properly.
Some don't.
Who knows what they pay or if they have part-time work or if they are family friendly.
That is something that also REALLY varies and you have to research it and see for yourself.... if you get called in for an interview etc. and research the organization, beforehand.
You are not too old.
It also depends on your job experience. And when that was and what you did, previously.
No one hires, non-experienced candidates. Per whatever job title you are trying for.
Corporate world or non-profits, BOTH have, bureaucracy.
So know that.
"Meaningful" work, depends on what you do and what you consider meaningful. It is not just dependent on the organization that you work for.
I currently work at my kids' school.
That, for me, is meaningful. In many ways. Not just for myself.
I used to work in corporations and non-profits.