I'm going to visit great wall on 9/1/2016. I'm a handicape person and able to walk with a crutch.

Ting, I checked the weather forecast. It will be sunny on Jan. 9, 2016. However, the temperature is very low. It will be from -9 to 1 Celsius Degrees. It's cold, isn't it? So you'd better warm thick and warm clothes.

Considering of your situation, I think you'd better use cable car to reach the top of the wall and then walk a few minutes to enjoy the wall. It's safer and easier for you.

Any idea where get the entry tickets?

Don, you can buy the entrance tickets to the walls when you arrive. There is no need to buy in advance.