Trap and skeet newbie
I've got over 50,000 registered target, so I'll share some advice-Take it for what it's worth(I was 9th in the state of Ohio quite a few years ago) Now like the Cleveland Brown's Bernie Kosar- I have diminishing skills. An 870 express would make you very sore after an afternoon of shooting. When going to a registered match for example, you will start the day with 25 or 50 practice. Then 100 16 yard targets. After that, perhaps 25 of handicap practice, if there's time(as a male shooter, you'll start at the 20 yard line). Then 100 handicap targets. If you so desire, then you shoot 100 doubles. No way are you going to shoot well in doubles with an 870, or any other pump. I've shot K-80's, Krieghoff's and 3 or 4 different configuration Perazzi's but the best scores I ever shot(especially on handicap from the 25 yard line) was with a modified remington 1100. I had an adjustable stock with an adjustable soft comb built for it. The barrell was backbored and ported, the forcing cone lenghtened and it was by far the softest shooting gun I ever shot. There were many times I shot 500 bird marathons in 16 yard and handicap. Then after those rounds, some doubles. You can use a shell catcher that slips easily onto the gun to catch the shell when only shooting one shell at a time. Also, so I didn't hit the shooter to my right, I had a dot(looks a little like this^) welded to the top side of the barrell on the inside. I works wonders by throwing the shell right at the ground by your feet. "ONE THING YOU NEVER, EVER DO IS PICK UP YOUR SHELLS FROM THE GROUND WHILE THE SQUAD IS SHOOTING. MOST CLUBS WILL NOT ALLOW YOU TO PICK UP SHELLS PERIOD, WHEN SHOOTING OR NOT I hope this helps you a little. As far as skeet, I shot a lot of it, but never registered. I didn't care for the repepitive, same o, same o. It is fun though to shoot it with a 28 gage or .410.
That's a lot more of a challenge. Another thing to look into is Sporting Clays. I simulates hunting more than trap or skeet. It's fun and really gets you into practice for hunting.
Go for it and have fun. Don't forget, YOU WILL WANT TO RELOAD IF YOU SHOOT. IT SAVES YOU ABOUT 60 TO 70 ON AMMO
Mickey