The west branch of Cascade creek is stocked and is really close to where we are staying. Well within walking distance. It might be the best option. Luckily my playing son only has one game saturday and sunday, both at 330. So I might get a little fishing in.
Have you ever fished Cascade Crick before? It's tiny and has a very small stocking area. I've only fished it in the fall a few times with my boys to save ourselves a skunking on steelhead when other cricks are blown out. I would imagine the stocked trout in the spring get hit pretty hard there, and if there's not a stocking within a day or two of when you'll be there, there probably won't be much left. But not positive on that.
If you want to fish for trout, it'd probably be more worthwhile to head to Elk. Probably won't be a lot of steelhead left, but you'd have a chance to get into a few. Smallmouth should also be pretty abundant in lower Elk from the mouth up to Rt. 5 by then as well, although probably not quite at their peak numbers. If you drift some minnows you'd have a good chance to get into all three in the same holes.
I like fishing on Presque Isle, but my sons don't care for it so I never did it much when we've been up there. There's a lot of water to fish around the Perry Monument - both on the Misery Bay side and the main bay side. At that time of year, on the Misery Bay side of the monument, you should be able to find smallmouth, perch, and pike. Some largemouth too. I've never fished the city side, but if you have a Facebook account look up Presque Isle Bay Anglers and you'll get an idea of what's going on there and all over the bay in general.
There are lots of places between the monument and Marina Lake to pull off and fish. The flat there is one of the primary smallmouth spawning areas in Erie. If they're in, that flat will be full of boats but you'll have room to cast from shore.