Give her a peice of gum and when she unwraps it on the wrapper write I love you .Or make a puzzle or buy that says I love you on it and give it to her .Or if gouging to a y sprigs game have one that annocments be " your name " loves " your gfs name "; or if u go to school have that on the midnight anoccments.
You can show her by knowing the things she likes and doing that. For example, my gf loves it when I hug her from behind. And when we go out and when we do different things. Find out what she likes and do it and she wiill feel that you love her. Also, dont do what she doesmnt like. And lastly, youi cant proove that you love someone in a day, it taakes time. That you re still there and still feel the same way means that you love her. Well, if you follow what it says in 1st of Corinthians 13