Can you download new guns in Counter Strike if Yes where do you download it from

Well all the guns in game thats all you can use. How ever you can download the skins for the guns to look different so lets say you are tired of the knife and you want it to look like a tomahawk you can download the skin for any gun or weapon you choose you can throw teddy bear but really in game it is a grenade. The skins are only visible to you and you only other players will not see it. You can download many skins and more at fpsbanana.com