I travelled a great deal for business mostly coast-to-coast. Everyone's advice is good.
For a 1 hour flight, I would try to check everything. Chances of the luggage being lost are really minimal.
That being said, you still need to think about what you cannot live without for a day. In your carry on bag, carry on underwear in case you bags are lost. Place all your meds in a carry on. Putting them in a ZipLoc bag makes it easy for you and the security personnel. Take a disposable toothbrush and a little size of toothpaste and a travel size deodorant.
Definitely call the AC about the water bottle regulations.
If your seats turn out to be the emergency exit seats, please change them because it is your first flight.
Layers are good. I know that you are in Canada, but it is easier to go thru security if you are not wearing sneakers or anything with a heal. Flip flops are great. If you can change into them in the terminal and put your other shoes in your carrying on, the schools will be scanned in the bag. You can change back before you are on board.
Layers, layers, layers! Definitely.
Bring your own food if you can.
Have a great trip!