No reservation: I'm planning to go to Simatai within next week.

I'm alone so i dont know how and where to start. I live in Wangjing Chaoyang near Dongzhimen. So I can take bus 980 from DOngzhimen and tell the driver I want to go to this secrion of great wall? After I get off the bus where do I go? Also can I just buy the ticket when I arrive the entrance going to the great wall? Is there a guarantee that I can climb even if I dont have a reservation since visitors are limited. Can I give you my number so you can call me? I have lots of questions.

Thank you