Hey Abemand23,
Your English is fine, don't worry about it
If you have just bought the game and it is asking you for a key to activate it, you just need to verify the game files in Steam.
This can be done by Right clicking the game (in Steam) and select "Properties".
Select the “Local Files” tab at the top, and then “Verify the integrity of the game cache”.
Once this is done you should be able to launch the game without it asking for a key.
Let us know if you still have issues as there are some other steps that can help resolve it too, this is just the quickest one that is often effective.