@tube77, you need to get in touch with the Ski School director at the mountain where you want to teach. All your questions will be answered. But sometimes it's difficult to get in touch with ski schools until close to opening. Where are you and what mountain is this?
The ski school will need instructors for times when the crowds are big and the instructor staffing is lacking. You'll be hired to teach at those times, not necessarily when you want to teach.
That said, weekends are pretty much a sure thing. Also holidays - instructors will be needed for Christmas-New Years week, MLK weekend, President's week and the weekends before and after, for school vacation weeks in your area, and so on.
To get the job you may need to make a commitment to teach X number of holiday days, and Y number of other days. This total can be 25 or 40 or more total days. You may have choices on how to get to X+Y days. That depends on how the ski school director assigns workdays.
As a part-timer, you may be assigned to line-up, or to the kid's program if it's still running given the issues associated with Covid. Line-up means you line up each time lessons begin and wait for an assignment. You may get one or you may not. Kid's programs are usually scheduled ahead so you'll know when you'll be working, and there will be no down time waiting around.
You may be given a choice of kids or adults, or this may not be a choice you can make. You will most likely get some training targeted on how to teach beginners to turn and stop, how to teach them to get onto and off the chair, and where to take newbies on the mountain once they are off the beginner terrain. If you charm the Ski School director, you may get assigned intermediate or advanced skiers. But this is not a given.
All the above reflects my experience here in New England. It may be quite different midi-Atlantic or Midwest or out west.
Besides that I have to remark that I am a college student and I would like to say that I have already written about
https://papersowl.com/examples/underground-railroad/ underground railroad, it inspired me a lot by the fact that where I do ski lessons this transport is very popular, so, the idea is that you don't actually have to focus only on ski lessons, because the clients are actually interested in stories about the ski place, that actually creates a lot of interest.