I'm 55 and I just started park last year (except for a bit of experimentation the year before). Along the lines of what Snowolf said about deliberate and considered progression, body armour is a must. I've got knee/shin pads, impact shorts, and a spine protector. And a helmet of course. You don't have to always wear all the shit, as slyder says, but definitely wear it when you're hitting the features.
I told my kids, "Someday, you'll have kids of your own." One of them said, "So will you."
-- Rodney Dangerfield.