If so, was it easy?
& how long did it take for to become pretty good at it?
It really depends how well you pick things up. For instance, I can’t read notes – never have been able to, I can’t read tabs either. I’ve played guitar for 5 years, off and on. I play by ear, I taught myself – no lessons – na da. Now, I can play pretty much anything I hear.
I can’t think of any famous people who taught themselves guitar, but a friends of the family (Charlie Farren – Google him) has been pretty successful and taught himself.
As long as you’re determined, nothing should stop you.