how long will it take to get to the great wall?

thank you so much for your reply, can you tell me how long will it take for train to arrive at Badaling from north station?

Also, do you just walk to the scenic area after you get out the train station? How long will it take?
I have an older person along with me, so I am little worry that she wouldn't be able to get the scenic area if walk too long. I heard there is bus to go there too, do you know where to take it?

thanks so much!
jan