Hey RacerBG, welcome to the community!
1. What types of games can be done? 3D, RPG, FPS etc....
Basically anything as long as its 2D. Technically, some 3D can be done, but it's not an easy process because construct wasn't designed for it. You basically have to code your own 3D engine with events, and that is a task that is not be underestimated. If you want 3D, you should really use something else like unity.
2. With what to start - which tutorial, manuals.....
I would actually recommend using C2 to learn on, as it has a manual and is quite similar to construct classic. Start here with the beginner's tutorial.
3. Is there exist good documentation for CC?
There is the wiki. Again, though, a lot of what is in C2 is very similar to what is in CC, so that would be a good place to learn for starters.
4. Does Construct support some advanced functions for 2D/3D games?
2D, yes, 3D, no.
5. What experience must you have to do games here? A languages, scripts, arrays?
You don't really have to have any prior game making experience.
6. Construct Classic versus Construct 2 which is better for you?
Construct 2. Better usability, less bugs and quirks, more actively developed and more frequent updates, exported games run on more platforms, can paste stuff between projects (can't do that in CC - don't try, even if it seems like it works it's an unfinished feature and can royally screw up a project), easier to reuse code, etc.
The only downside to C2 is it's still relatively early in development, so it's missing some features like families, which allow you to use one piece of code to control multiple objects, though those are being currently worked on as the next feature.