Back in ‘07 we did a family road trip through the Rockies, which was a big loop of Edmonton > Jasper > Mt Robson > Kamloops > Jasper > Calgary and back with a bunch of detours in about three weeks. My time in Calgary was spent mostly studying, but I did do a bunch of smaller easy hikes because I’m not at all experienced as a hiker. I remember Ptarmigan Cirque off the top of my head as a nice one. Really, just browse AllTrails and pick a few that look good. The Alberta / BC parks websites are also filled with information.

My personal recommendations would be to try and get a glacier tour - I didn’t and I still kinda regret that. Lake Louise is a beautiful tourist trap, but worth it just so you can say you’ve been there when it inevirably gets posted on /r/earthporn again. I remember Bow Lake as a glass-like pristine beauty - all of the 93 from Jasper to Banff is gorgeous, by the way.

Also check out Wells Gray national park and the parks south of Kananaskis (e.g. Peter Lougheed), which are just as beautiful as the bigger parks. Most sights aren’t easily accessible by public transport, IIRC. The more popular villages and resorts are, but if you go hiking a lot I don’t think you’ll regret the flexibility and storage a car has to offer. I went with a regular rental company and have no qualms against them (besides their infuriatingly expensive pricing for younger people).