Alternatively, you may also pick the pre-made pro-player crosshair that best suits your style. The map currently has 80 crosshairs that you can customize using the settings board on the map. Once done, go ahead and walk through the small door into the bot field to test your brand-new crosshair.
A simpler way to use your new settings is to copy console commands from the crosshair generator instead of config and paste them into the game console. However, this procedure may need to be repeated each time you play CS2, so using a config file would be more convenient.