You're never too old to do parkour because you're never to old to play. Heck I've seen guys in their 80's do parkour so I think you'll be fine. Seek proper instruction and take it slow to get into but ultimately it'll be up to you for how far you go. Have fun!
You are never to old to give something a go. If you don't try, you will spend the rest of your life wondering whether you could have done it or not.
You're not too old but you should get some proper instruction so you can learn it safely & develop solid technique that you can build on.
No., yu r not.