Hi there, it's never too old to pick up an instrument, all it takes is courage.

Violin's harder imo. As they are fretless, you'ill probably spend most of time in your early lessons learning how to fret the notes, before actually playing a tune. That shouldn't put you off though... with passion and dedication, I'm sure you would be fiddling in no time. So, good luck!

Not too sure about violin teachers or violinists for that matter. Sorry, can't help.