WHEN DID RINGO FIRST PLAY WITH THE BEATLES? I HAVE READ THAT HE PLAYED IN THE CAVERN WITH THEM IN JUNE 1962 BEFORE OFFICIALLY JOINING THE GROUP.

I think that's true. I think Pete Best wasn't able to make it sometimes (not sure if he really couldn't come or just didn't feel like it) and then Ringo would play with them - John, Paul and George did already know him from before, of course. So I guess when it came time to find a new drummer, George, Paul, and John already knew he'd be perfect!