This is a nice driving road that allows you to come back to town in a short period of the time, or you can spend all day there, it depends on how you do it. You can stop at Lake Minnewanka for a light walk or boat cruise (there are washrooms). Stop at Two Jack lake for a picnic and watch locals fish or canoe (there is an outhouse). Go to Johnson Lake and walk around the lake or watch locals swim on a hot day. You may see Big Horn sheep between Lake Minnewanka and Two Jack Lake.
To get there drive North on Banff Ave towards Highway 1, pass the Highway and keep going North. Follow the road or take your third right. This is a loop so either way is fine, but I prefer following the road to Lake Minnewanka first because you can find the Johnson Lake turn off easily.