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.
In retrospect, "Let's get the goat drunk"
should have been my cue to leave the party.