If you're paying for a dedicated (hosted) server, then ask them for help.
If you're using dedicated server, you install CSS the same way you installed Gmod, but with different commands as you just typed.
If you're using Listen server (hosting from your game), you only have CSS if you already have it installed.
Please use Off-Topic for questions like this. You keep posting in "ULib/ULX support only" thread and should not.
Also, since you have a hard time understanding english, you maybe should find someone who can help you in your own language.
Those instructions are simple if you know english.