My experience in provincial parks for shore fishing and occasionally on canoe/sup.
Around Simcoe Lake:
Sibbald Point PP - we've camped in this park with the group several time ~10 years ago. I had own luck with rock basses and panfishes; witnessed how others caught a nice bass and a cat near the ramp. Later visited park for a day almost every year spring/summer/fall. Though fishing was getting worse and worse. Last Sunday - just gobies and small perches. I put a cross not to go there for awhile.
Mcrae PP - quite shallow around the park. Small ramp. Though not that busy as Sibbald as it is further to go. During summer I waded till waste and caught perches.
Mara PP - as I remember a very short strip of water and it's a beach.
Going East to Toronto:
Darlington PP - with access to Lake Ontario - only day visits, never fished. There is a pond or a lagoon maybe with carps
Persquile PP - a nice park. Fishing - no luck with big ones. West side is quite open to the lake, and it could be rough. East side is like a bay, there is a government dock.
Sand Banks PP - a busy busy park. There are private campgrounds around and people go to sand dunes of the park. Have not tried fishing yet, probably there are opportunities in the West Lake. In case you'll have time go and visit a Lake on the Mountain PP to learn about wonderful geology.
North East:
Emily PP - a small park. We camped once long time ago. As I remember the river/bay had troubles with a carp disease at that time. You can rent canoe and go even to Pigeon Lake. Though there were spots for share fishing too.
Bon Echo PP - a nice park. It could be busy too. A lot of opportunities for fishing offshore too.
Silent Lake PP - a nice remote park. We camped in a walk-in place. A lot of great places to fish alone or with kids. Canoe gets into remote and weedy spots for basses. No motor boats. One remark - a park is very rocky, be careful when selecting the site. Some could be not great with kids as you might worry they can slip and fall of the cliff.
Balsam lake PP - one of our favorite - we go for a day and camp once a year - a nice beach, a playground for kids, possibility to rent a canoe or kayak. Several spots for offshore fishing too. Some years were better than other. What could be better of a fog, a loonie, and a fishing rod on the rising sun
West on Lake Huron:
Pinery PP - a big park with many sandy/gravel beaches. Through the park goes an Old Ausable Channel with possibility to fish from bridges - one close by the park store and canoe rental - a daughter and many other kids had a great time with small fishes. Other bridge on the other side of the park gave possibility for basses, a pike, and it looked like carps were swimming around too. An old snapping turtle came several time for a visit too.
MacGregor Point PP - no fishing unless to go outside the park to Saugeen river (never done), though saw in one spot a lot of people.
Sauble Falls PP - some campsites are on the river. I had a habit to catch one bass each morning in the same spot for a week and probably the same due to C&R. After going to the beach, we would stop to fish at the river mouth - full of basses.
On Georgian Bay
Awenda PP - a nice park with rocky beaches. The small in-park lake has spots for fishing.
Killbear PP - a huge park with everything. Evenings for trouts.
North
Bass Lake PP - a small park. It has a ramp with a bridge for good panfishing for kids.
Arrowhead PP - enough spaces for offshore fishing for basses and other panfish. Though canoe/kayak would open more opportunities. I used a stand up paddle board (sup) to go around the lake with a great success for basses this year.
North West:
Six Miles PP - requires some wading to get off the shore and trees - pike and bass.
Grundy PP - looked that small pikes were everywhere like panfish in other parks
without a direction:
Earl Rowe PP - the lake water is far from crystal clean (thus the park has outdoor pool
though a lot of spots for fishing. Took a canoe and went down where the river clears up - saw carps swimming there. Maybe some of them are in the lake too.