Personally, I don't catch that many fish around the park. I catch a few, but generally have better luck upstream.
I've caught Bluegill, crappie, largemouth, smallmouth, goggle eye.
I've heard even farther upstream, is some better fishing, but I haven't been up that far yet.
I'd say earlier in the morning would be the better time to fish it, before all the boat traffic picks up too much.
But don't expect to catch a ton of fish.