Can anyone give me some advice?:) girl aged 14!?

[Lucy]

Ok, so there's a guy who asked me out 2yrs ago and I said no and laughed at him.. ( I didn't know him and it was what I thought in my head not was meant to come out) he then didn't speak for a year... Then we chatted a lot and since September I've really fancied him! He chats to me a lot as he does with everyone.. I flirt with him but he doesn't really respond.. I messaged him a month ago on twitter and we were chatting for a night then i said maybe we'll chat tomorrow, he said yeah sure but he didn't realise I meant it in a romantic way! I really want to go out with him but don't know what to do!! As shamefully I've never been in a relationship as I haven't felt ready. Please help! sorry for the long message!!