Please refer to the Canadian Government website for the most up to date travel requirements: https://travel.gc.ca/travel-covid/travel-restrictions/exemptions
View this website for information regarding your trip to Banff in October: https://thebanffblog.com/banff-in-october/
The elevation of Banff is 4,537 feet. Although you should not feel too much of an elevation change, you definitely can should you decide to hike. Please be mindful if you think altitude could be an issue to contact your physician for medication prior to your trip.
Most all pricing shown on a website for Canada will be in CAD, so we advise using a World Currency Converter app on your phone should you have any questions while on your vacation.