1- Does it exist a flight merging flight and helicopter? like harrier?
Yes, there are. But for a beginning pilot they are a very poor choice due to the complex skills involved in flying them.

2- What is the fastest airplane?
The ones made for high end pylon racing are the fastest.

3- Whats is the airplane which has the max length of fly?
Do you mean longest time in the air? Overall, sailplanes can spend the longest time in the air since they don't use fuel or motors. For powered flight, flight time is determined by the size of the fuel tank and the way you fly. Most pilots can't keep focus longer than around 15 minutes though, so flight length is really not a concern.

4- Does there exist a plane with camera to see what it sees?
You can put a camera in nearly any airplane. It is called FPV camera (first person view). There are also simple cameras to take pictures and video from the air that you can see after you land.

5- Does there exist a silent plane? Without terrible sound while flying?
Any electric will be quiet, but not completely silent.

6- Does the plane come with remote control and motor or no?
Some vendors sell RTF packages with everything, but you will get the best equipment that will work with future planes better by buying it seperately.

7- How can I learn how to flight?
The best way is to find a club near you and get training from an experiened flyer using a buddy box.