Where do I put my discussions?

First of all I hope I put this on correct place for my discussion :P. If I wan't to ask a stupid question like http://boards.eune.leagueoflegends.com/en/c/off-topic-en/Noi7RjlA-how-tall-are-you-instead-of-cm-it-teemo?comment=0028 Where shall I put it? There is 12 places for discussion When and how will I use them? (I don't understand NA Boards)