>>8
Shit, viola is harder than violin. Violin rep is harder but viola is a bitch to play physically.
If you want to start learning violin at this age, get ready to sound like shit. You're going to have no bow control for at least the next 5 years. Your intonation will suck balls as well. No sense of time. And you're not going to have any coordination.
Get a good teacher, one that teaches lots of adults and high schoolers but also knows how to start 4-year-olds on the violin. Also, DO NOT BUY A SHITTY $40 VIOLIN-SHAPED OBJECT OFF OF AMAZON OR SOME SHIT. They're are only good for smashing, which you might want to do to your violin several times...
If you want to learn a stringed instrument that's easier to play, I'd go for a gamba, but they're not really that popular so finding a teacher much less acquiring a gamba would be difficult.