Well, first of all - can you use another word besides "elderly"?
Anyway, I played "at" tennis a little as a kid, but never had any formal lessons. I'd say I never got past the 2.5 level. This was back in the wooden racquet days. (Really!)
At 40 I took up the sport seriously. The first thing I did was join a club and take a series of "Intro to Tennis" group lessons for beginners. I've stayed a member of that club ever since. I've taken lots and lots of group lessons, drills, some private lessons, and spent (in total) a month at Newk's and several other weeks at several other tennis resorts and camps.
I've always played in Singles and Doubles leagues at the club. After several years I joined the USTA. I was originally rated a 3.5, got my butt kicked badly for 2 years and was bumped down to 3.0. I started a 3.0 USTA team with a bunch of other guys that gut bumped from 3.5 to 3.0 and we went to sectionals. We took 2nd and most of us got bumped back to 3.5.
Since then I've been playing 3.5 USTA leagues and tournaments, with varying degrees of success. I think I was ranked in the top 20 (at 3.5) in our section (which sounds nice, but really isn't that big of a deal) several times.
A couple of weeks ago, near the end of my 51st year, I got bumped up to 4.0. That's my tennis life in a nutshell.