I started age 13 with a horse on loan (completely unsuitable really but I learnt a lot) he was kept on a riding school/livery yard and the experience/help was invaluable. He was on turnout livery so each morning was fed, rugged and turned out for me... Every tea time I got the bus to the yard, mucked out, hay, water, fed, groomed, rugged and then bus back home.
I loved it.
At 16 I loaned on a hunting yard, never hunted but I competed the horse all summer as he was basically my own out of hunt season and around hunting we also show jumped and dressaged so he was kept fit as a fiddle. He was my absolute life and I was there twice a day, every day even Christmas. This continued when I had my own horse and until we lost her approx three years back even when she was basically an expensive pet due to her ailments.
It's hard work, takes over your life and is expensive however... I was mature, sensible, responsible and dedicated. It taught me a lot about hard work and commitment.
For my parents it was an ongoing cycle of taxi service, handing money over and travelling to lessons etc but they preferred that to me hanging around the streets etc
Would I recommend it 100% but be prepared for early mornings in the dark, with shit weather and sometimes no elecrric if you go DIY route