What do girls like neeed help plese :) ?

How should I go about myself trying to get this girls to like me I am 13 and I really love this girl were both the same age and of the same intelegence (both top). Weve always been good friends but never any further.she dosent know I love her but in the past(about 3 years ago) I told her I fancied her but we fell out and I told her I diddnt. Recently I cant stop thinking about her and its takeing my life over. When she moved school when this started to happen (no reason to do with me) I was heart-broken, so I decided to play out with her. I played out with her a few times and I started to have suspicions that she liked me. As she asked ‘’if I asked you out what would you say’’. I was embarresed about this so I changed subject but as I lefed I left a note saying’’probably yes’’ and I think she saw it. I only saw her once after that but we wernet allowed to play in her room so we diddent talk about rude (lol) and sentimental things like we useually do (her mum was neer us).im nervious to go so I havent seen her for 2 weeks (I also havent had chance on the days when I would have gone). How should I approtch thice and how do girls feel. Ps. Im also worried that she might think that were boyfriend and girlfriend in wich cace id be in deep troble. Help would be greatly apreciated thanke for reading. :):):):):):):):):):):):):):):):):):):):):):):):):):):):):):)