BC (British Columbia) and Banff are two different locations in western Canada. Banff is located in the province of Alberta. Not far from BC which is split from Alberta by the Continental Divide, but if you are flying into the coast of BC, then it is a bit far.
Canmore is where you want to fly fish or at least hook up in that direction in terms of beta, equipment, guides, etc. Rules and regulations vary greatly within the National Parks versus Provincial Parks and designated wilderness areas.
Kananaskis Country (a very large Alberta provincial park system) is where the local river kayaking is if you are into anything above class 3. The Bow River is mostly just a nice canoe trip, whether from Lake Louise to Banff or Banff to Canmore. Lake Louise to Canmore, running an interesting waterfall in Banff, would make for one very fascinating (but short) moment.
Any of Alan Kane's easy scrambles
in his most excellent scrambles guide book, covering Waterton National Park to Jasper, should give you solid class 3 objectives to ponder. Most of what he calls moderates to difficult can easily lead to sections of 4th and 5th class, ice, bears, etc.