Where to add meta tags?!

Hi guys!
I am about to turn grey now after my searching!
Basicly i would like to add meta tags, but now I can’t find anything else than CSS. I can recall there was something else you could go into on your blog where you found vody, footer, header and so on, and actully could fix an change with the codes.
But now I can’t find where theese codes are, seems like that option is no longer avalible only css. Is my blogg corrupted or am I blind LOL.