I think I am a good case study - I started riding park when I was 32 after many years of riding mainly steeps and pow. I am in the industry and I ride park almost every time I get out on the hill. You are definitely not too old.
What you have to remember, though, is that you and I are not as elastic as we used to be and indeed as elastic as the kids we are riding in the park with. I have seen some of the most horrific looking slams where the kid just popped up and gathered his shit like nothing happened - a slam that would have broken something on me. I had a rather simple fall off a flat down box last winter that resulted in a torn shoulder muscle that took months to heal.
There are two things I would advise seriously - Go slow with your progression and get some pads. I have taken a lot of time getting really comfortable on rails, boxes and jumps without tricks and have been nailing 180s, sw180s and zeros for a while. I am now to the point where I am working on spinning 3s and spinning on and off boxes and rails. Most of the kids who frequently ride park will get through these skills much faster than I have, but I can't afford to hurt myself like when I was young. I also pad myself head to toe - downhill mountain biking shin and knee guards, impact shorts, impact jacket, mouthpiece and helmet. It helps a lot.
Regardless of padding, however, you will fall on your hip learning to jib, and you will get some of the nastiest bruising you have ever seen - It happens and has happened to every single one of us who rides park. You just have to pick yourself up and do it again.
Enjoy