Hi Lisa,
I was 41 when I first travelled with JY, that particular year I was the youngest of the group but did not find age an issue at all. The following year the age range was from mid 20s to 79. Everybody mixed well, My advice would be to pick somewhere you have always wanted to go and take the plunge.
I have to travel from Northern Ireland to meet the rest of the group, have only good things to say about each of the holidays I have been on.
Janice