I think you will be fine. a buddy of mine uses a 870. He does fine with singles trap. but when you start getting into skeet and doubles trap, he's at a significant disadvantage.
seriously thinking about trap shooting...How effective will my mossberg 500 be on a trap range.. talking equipment, not talent.. I do pretty good in IDPA. I know two different worlds.
Trap is one of the few sports that you can bring a $79 H&R topper, a $300 hunting pump gun or a $75,000 Custom ordered and engraved S/05 Beretta and have equal chance of running a straight 25 bird round. Any gun with a modified or tighter choke can get the job done. If you are really a quick shooter, you can even do pretty good with a cylinder bore.
The first 50 in a row I ever ran was with a well worn modified choke Mossberg 500 pump at the Griffith Izzak Walton League. I have done it since then, but that one was special. Don't worry about what you bring, just enjoy the fun.
Skeet is a little tougher if you have to shuck the pump to shoot doubles.