I have recently started working with Unity on Windows. And I want to understand how to move in the scene with arrow keys.
For ex., I create a cylinder in the scene. When I press “Build Run”, I see only this cylinder if the camera sees it.
All is still.
How then can I make moving in the scene using arrow keys, so I can go around this cylinder and the scene will render?
Also about moving the mouse. I want to move camera corresponding to the mouse.
Please help with implementing it.
I think it must be a common procedure to implement it, as usually any scene has possibilities to go there and move the mouse to see around.
If you include the Standard Assets library in your project there will be scripts/prefab with this already set up for you (movement with keyboard, mouselook, and so on). I believe they are called things like FPSWalker.js and Mouselook.js or something similar.
Failing that, just open up the Island Demo project that comes with Unity and have a look there, as it has a working example of an FPS-type control setup that will show you how it’s all set up in a scene as well.
Thanks, by the way, FPS means frame per second here, or not? 
Also, moving is possible only if there is some ground under user?
In this case FPS means First Person Shooter, since that’s the style of camera and character control the script creates. And yeah, that particular script (unmodified, anyway) requires ground for the character to walk on.
During the tests I’ve got a problem - the coordinate grid has disappeared somewhere, I’m trying to rotate, move etc. but it is unclear where is it. (I mean in the editor, not builded yet)
How to get it again in the center?
Also, standard assets now in my new project (created automatically), but must I do smth for their work, that after build I could move in the scene?
Ok, grid has appeared after selecting Window → …
But I’ve created a plane, on which camera stands, but walking and seeing with mouse doesn’t work.