I would like to have a simple begin: how to get the game render window up, how to get game logic and game python scripts running? Cannot find anything in Blender’s menus and dialogs. Could not find anything this basic in forums and wikis.
I created simple terrain in the main editor. Now I would like to go into the game mode and interactively access the terrain data. No true 3D rendering is required at this phase. I likely start by assigning keys and mouse to run python scripts.
You can manually rearrange the blender interface to show the logic editor window or just chose the ‘Game Logic’ interface layout from the tp of the blender interface (by default set to ‘Default’). Next to that you can change the render engine from ‘Blender Render’ to ‘Blender Game’
You describe the behavior of the currently selected object in the Logic Editor.
The BGE runs Python code via Python controller. Any other way to run Python code (e.g. text editor) is Blender not BGE.
To get the basics of the BGE you can read the Guides you find in my signature.
Have a run through a tutorial such as this:
http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/An_aMAZEing_game_engine_tutorial
Things have changed a little since the tutorial was made, but most of the interface is similar enough.