Not stupid at all to ride park at 40, and more people do than you might think. Was in a rail jam with a guy in his early 40's last year and he was having a blast.
The key (at any age) is to work your way up to it. Most resorts have a smaller sized park for people just starting out which means less height, less of a gap to the landing. Before that though, find a roller and pop off it. Don't bomb the slope before it and fly into the flats, you want to catch the downside of it and practice matching your board to the slope of the landing, with time that will come natural. Make sure your shoulders are square with the board the entire time. By entire time I mean riding up to it, popping off, in the air and landing, it's common for people to want to open up their shoulders so they're facing down hill but fight this and keep them square to the board. Always stay centered over the board as well, front to back.
Once you get comfortable doing this, you can move to the smaller park, sometimes called a Progression Park. BEFORE hitting anything, ride past it. Check out the lip and the landing. Depending on how often a park is grommed/raked the landing can get rutted out. If everything looks good and you feel you're ready for it, find out where others are starting from and gauge the speed you'll need to clear the knuckle and land in the sweet spot. It's important to remember that different snow conditions may take more time to build up the speed to get to the landing. A lot of smaller jumps have less of a knuckle which means less consequence for coming up short, but take my advice and don't hit a smaller jump at full tilt so you don't overshoot the landing. I think we've all done it, and it's fairly common to see beginners doing it but there's no worse feeling that the "oh shit oh shit oh shit"
As you're riding up to it, again keep the shoulders square, weight centered and don't over do it on speed checks, if at all. You should have a general idea of how fast you need to go, and after the first try it'll be a lot clearer. If you're overly nervous, take a long deep breath as you're riding up to the jump to calm yourself down, it absolutely works.
When you're in the air pull your knees up, try not to tense up and lock up your body. If you can, do a grab. When you're first starting out Mute and Indy are generally the easiest grabs and can help keep yourself balanced as long as you do it with your knees-legs pulled up (not reaching for it).
Spot your landing and extend your legs to meet the landing, absorb it and ride out.
From your post it sounds like you have enough ability to do it and ride away, but if you crash just move out of the way because you might not be visible in the landing for the people on slope above you. Even if there's an injury, do whatever you have to do to get out of the jump line. Just remember crashes are going to happen anytime you start learning something new so don't get discouraged. Start small, work your way up to it, and have fun with it.
Edit: I completely agree on the pipe, in my opinion it's one of the funnest things to do on a snowboard and when you're starting out (in my experience) the crashes are much easier to take.