I have a Harbor Breeze Armitage ceiling fan that was installed about 2 years ago. Several weeks ago, I turned it on at the wall switch as usual. Athe light came on but the blades do not move. I hear a humming noise when it is turned on. I have read about a "capacitator" part that may need to be replaced. How do I know which piece and where to get it? Thanks!

It is usually in the housing, and could have 2, 3, or more wires(multiple values), you would need to open, identify, obtain and replace.
If you spin by hand to get started, will it start?

Do the blades turn freely by hand?

General ceiling fan troubleshooting and help FAQ- Ceiling Fans N More

BTW the Armitage is a REALLY cheap fan. If you got 2 years use out of it, you are lucky.