There were 3 types of people on my course
1) The young ones mostly doing it as part of their DoE award scheme
2) The slightly older ones, most of whom saw it as an 'easier way' to earn money than doing a traditional Saturday job
3) The more mature ones of us who wanted to give something back to the game.
As far as I can recall, most of the ones in the first two categories have disappeared without trace. There were 5 of us in the 3rd group, 1 has given up, 1 only ever wanted to do it as he was a kids coach and wanted to be able to referee them properly when they didn't get refs appointed, 1 is a L5 (who can't pass the fitness test to get to 4) and 2 of us are L4's.
Don't fret about your age, it's really only a massive problem if you are aspiring to get to the FIFA list and haven't started in your early 20's at the very latest, otherwise it's not an issue at all.
I've mentioned this before on here but I couldn't get qualifying games after the course as they gave them all to kids who were doing refereeing as part of their DoE awards and had no intention of refereeing. I had to go to another county to get my qualifying games in and then I transferred to them permamently because they supported me with games. Literally 3 weeks later I was contacted by the leagues in my parent county as they were short of refs as most had not actually bothered to referee more than 1 game before giving up.
I understand the need to prioritise young refs and didn't complain, I just made my own way and my own contacts. I suppose the best advice I could give to a young ref who's thinking of starting is to make your own contacts. Do things off your own back as well as seek help from the RDO