Brockville run along the St. Lawrence River in which holds a variety of different species. LM & SM Bass, pike, musky, walleye, trout the list goes on and on. A few times a year I visit relatives about 30-40kms east of Brockville so I have had a chance to explore a bit over the past few years. When I don't bring my boat along I have to fish from shore so I usually try and find spots that are easily accessible and that provide ample areas to cast. I'm mainly a bass fisherman, dropshots and tubes work great in the river and jigs with minnows with pretty much catch anything that swims.
If you are there for such a long period of time I would do as much exploring as you can, try different baits, talk to some locals etc. Also, check your regulations as well to see whats in season and whats not in season!
I was lucky enough to be in town in 2013 When the Bassmaster Elites were running their tournament out of Waddington NY on the St. Lawrence River.. I was fishing among the best anglers in the world... had KVD floating down the river beside my boat. It was quite the thing to see.
Anyhow, good luck with your training....and fishing!