I started keeping last year on a whim. Bought a pair of gloves and found I had the eye for it.
Wouldn't say I can do it perfectly yet, but I'm pretty handy behind the stumps.
Doubt there's a right or wrong time to start as mentioned before.
It's never too late to start.
Though always wear a helmet standing up. There was a keeper playing in the ground next to us yesterday who had to have stitches in his head as the ball grazed off it..
Luckily it wasn't any worse.
Great thing to do is keeping, if you can endure it for 40+ overs. As it helps your fielding when you field and it is a good way of earning promotion up a team