A simply answer for you.. you are as old as you feel! Whilst the average age of attendee's to ConFuzzled might be in the age range of 18-26, there are many conventions, for example, in America where the age group spans a much wider range, some in their 60's and 70's.
There is no given age of when someone should or should not start fursuiting. One of my friends daughter has a fursuit, she is eight. At the same time, I have a friend in the US in his late 40's and he is an avid suiter, plus he makes his own.
Age doesnt make a fursuiter, but ability. If you can bring a character to life, then you are never to old, or young, to be a suiter.