I'm a new guy to photography so recently I bought a Nikon D3200 camera with an 18-55mm lens. So I just want to know is this a good camera to use? What is the longest lens I can use on this camera? And also, can I record very good quality videos with this?
If you can find one for sale there is the Zoom-Nikkor 1200-1700mm f/5.6-8P IF-ED.
B&H Photo recently had a used one offered at $99,000 USD.
Most generally speaking, any lens with AF-S designation (speaking of Nikon lenses) or any third party lens (with Nikon F mount) that you know has AF motor built in. Also any Nikon lens with 'D' suffix, but as a manual focus lens (AF-D lenses rely that the body has an AF motor and D3***/D5*** bodies don't have one).
Look here, more specifically the 'Compatible lenses' section.
As Kamen mentioned, you can use any AF-S designation lens. However keep in mind that your camera hasn't a Full frame sensor (Nikon FX), it has a Nikon DX type sensor, which is smaller. That means that if you buy a FX lens, it will fit in you camera and you could use it, but the area covered by you lens won't be the one registered by your sensor. It will be cropped.
There isn't "the highest powerful lens", there are some with higher aperture, others with higher angle of vision, others with better chromatic performance... you won't probably find the "best of all", each one has its advantages. Just buy an appropriate for your needs.
The current longest production lenses you can get for Nikon F mount are:
Note that, because your body is a 1.5 crop sensor (DX), the above lenses will have a same field-of-view (i.e., more apparent "reach") as a 1200mm lens on a full-frame (FX) body.