To be fair, I first started modding when I was 12 so age really doesnt matter tbh. What matters is the maturity and how you are able to say, manage your time, be respecful and humble about it, and know where you need to put the work in.
Modelling isnt an age exclusive thing, it just requires a good sense of space and form which can be learned. It isnt a 100% thing though, some people doing modelling can get the shape perfectly, others like myself, not so much.