There’s not much ready for beginner skiers yet, but if you’re willing to drive to Lake Louise, the best trail by far is the Great Divide(aka “Old 1A”).
In Peter Lougheed Provincial Park, some of the trails leading out from Elkwood Amphitheatre are reasonably good for beginners such as Wheeler and Lodgepole. Both of those trails have been roller packed but they will not be trackset until there’s more snow.
The trails which have been trackset in the south end of PLPP are very difficult with sustained steep climbs which turn into extremely fast downhills on your return. This scary video shows a skier descending Elk Pass The fastest 1 K in Kananaskis.
Another trail at Lake Louise which is worth considering is the Bow River Loop. It has recently been trackset and offers some amazing scenery on a clear day. The issue for beginners is that it’s only single track and very narrow. You have to be ready to get out of the tracks when meeting other skiers.
I’ve found the most enjoyable part of the Bow River Loop is the south end starting from the campground bridge. It avoids road crossings, is about 4.5K and is dog-friendly. Read more about the Bow River Loop.
The photo below shows skiers gliding downhill to the BC border(the “divide”), at 6.6K. Depending on conditions and your ability, you may need to snowplow. If the hill is too intimidating, you can simply turn around at the top and head back. 13K is a lot for a beginner skier anyway.