Great Wall of China visit, can anyone advise me an itinerary for this ?

Mitali, the nearest section should be Huangyaguan Part. First, take a taxi to Hebei Bus Station in Tianjin. Then take regular bus from Tianjin to Jixian. Please take the express buses because they run on the highway. The buses are available from 07:10 to 18:30. It costs CNY 52 and takes around 1.5 hours to Jixian County. From there you can take a taxi directly to the scenic area. It costs CNY 75. If the driver doesn't use the meter, you need to bargain with him.

If you don't want to take a taxi, then you might take a three-wheeled motor car from the bus station to Xiguan. It costs around CNY 5. There are many vans for Huangya Pass. It costs around CNY 10 to 15 per person. Also you need to bargain with the driver if he carges too much.