Hello.I would like to no which bus i would take from Beijing airport to Tainjin city.

when you are at the PEK (Beijing) airport on ground transportation level there is a "long distance bus. The bus stops at each of the terminals. The ticket was 86RMB the last time I took it. Generally the journey takes about 2 hours, if I remember right.

It is not difficult. I would recommend having the address to the location that you desire to go in TJ handy to show a taxi driver when you arrive. There will likely be a number of drivers, but the pushy ones might not be the best to use if you don't know where you are going or speak Chinese.

I hope this helps. Welcome to the TJ International Fellowship if you will be staying for some time.