I'm very amateur at shooting at clays.
I started with a used Yildiz O/U I got on the cheap. It is too light, and beats me up. Shoots good though.
I bought a Mossburg O/U for around $700 new. I shoot this pretty good, and it's a joy to shoot.
I picked up a used Store branded AyA Matador SxS on the cheap. It's box lock design will never go loose. It shoots well for me, and has a generous amount of cast that makes it point like a dream for me. I shoot it quite a bit, along with my Mossburg.
I recently picked up an Armalite AR-17 for a song. I had to fabricate an extractor, which is why it was so cheap. To say it's light is an understatement. I've shot a box of Estate #8's Target load through it, and I wouldn't want to shoot it all day, but it wasn't as bad as I expected. The short recoil action seems to absorb quite a bit of the recoil.
If you locked me in a barn, and told me to shoot the broad side with it, you'd probably need a roofer. I do not shoot it well. It's too light, and the Monte Carlo style stock encourages me to try to shoot it like a rifle. It's a great example of what NOT to get in a shotgun.
It will go, as soon as I'm done with it.
If you're looking for new, I'd recommend a CZ O/U. It's affordable, and will serve you for many years.
If you're budget is more limited, a nice 1100 can be had fairly cheap, or even a used 870 Wingmaster pump gun. The older Wingmasters are so slick that they're a joy to shoot.
I once got schooled in skeet by a kid with a cylinder bore 20ga Mossberg Maverick. I was shooting a Beretta SP. It's more the shooter than the shotgun. There's just a smidgen of skill involved.