Please help

There is a Girl that I really like and we are best friends. I want to ask her out but I'm she says no it will ruin out relationship as friends. I believe she show sting signs of her like we such as: My headphones were around my neck and she pull me towards her and was touching them and we all ways go for skates together. Should I ask her out or just stay friends also what should say too ask her out and what will I say if she says no?

The answer to this question totally depends on how she views your friendship so you will have to get that answer from her. You don't have to have a formal agreement to date. If you enjoy spending time together, just do that and if she develops feelings for you, it will become obvious. Sometimes people become more than friends before they realize it.