Need to Travel By Road from Karachi to China

By road in Pakistan takes always longer than expected. I advise you to fly to Islamabad since flights to Gilgit are not always running, From there you have two options: bus (unending hours on very bad, bumpy road, sometimes broken,too many controls) or taking a shared/chartered 4WD taxi. Even with this last option you'll end your road journey at Attabad lake, splitting lower Hunza from Upper Hunza. You must be carried on a boat (some 2-3 sailing), no cars on board so far to Gulmit and then again look for a taxi (no buses). From there you can reach the Khunjerab pass in 7-8 hours, depending on the road and then find another road transport into China (Kashgar).

I did it as advised and it's been one of the most enjoyable trips in my life. So, wish you the best. If you can split your journey to get to Fairy Meadows,from Chilas, then stop in Karimabad or Aliabad and do some day treks to some glaciers and peaks viewpoints over Hunza, these are highlights.

Firstly, how would you arrange a Chinese visa?

You can't to get the Chines visa if you re a Pakistan and going to China for first time.You have to be minimum five people in a group if you want to visit China...as a Pakistani first timer,no hope otherwise.

you can do the trip from Karachi up to the China & Pakistan Border it is possible.