Don't you people watch the Geico commercials? It's a European shoulder bag!

!
Seriously - each passenger is allowed (but not required to have) one carry-on within the airline's listed dimensions that fits in the overhead compartment wheels-in or handle-in; and one personal item such as a purse, laptop, Jansport, etc, that fits
completely underneath the seat in front of the passenger.
Canes and crutches (along with other mobility/medical devices) don't count toward your carry-on limit. They will likely need to be stowed overhead during takeoff and landing. DO NOT LET GO OF THEM UNTIL ALL LUGGAGE IS STOWED, said the voice of experience. A helpful FA took my cane in the middle of boarding once, saying he'd get it for me if I needed it. Well, on a five+ hour flight, I needed it. It was buried in the middle of all the luggage.
If you have a coat, jacket, etc., please hold it until all passengers have stowed their overhead luggage. If there is then room, you can put your outerwear up there, otherwise hold it, use it as a pillow, use it as a blanket...
In case of an oxygen loss, masks will drop fro... oh, never mind. The Flight Attendants can handle the rest of the preflight talk!