Example:
@import url(http://fonts.googleapis.com/css?family=Comfortaa);
body { font-family: 'Comfortaa', cursive;}
I agree not the best way answer but it does give you enough information. Go to your Appearance tab, then select the CSS tab, in the edit CSS field add your @import code, below that line I added a body{} but you can do it more specific if you want.
Example:
@import url(http://fonts.googleapis.com/css?family=Comfortaa);
body { font-family: 'Comfortaa', cursive;}
thank you but want to change espacialy main menu