Hi there.
I am in my early 50's and going with JY for the first time this year as well.
If you are unsure why not try the discovery weekends I did and enjoyed it so much booked 2 more holidays with them. Russia in August and Thailand in Oct.
If the holidays are anything like the discovery weekend, the other comments are correct in that everyone mixes in well.
Just rememeber we are all in the same boat, on our own and wanting to get away.
Go for it and enjoy whatever destinantion you choose.
Good Luck
Glenn