Be yourself dont try to act cool. She will only like who for who you are. You can show emotions but dont seem too desperate and if you try to act cool and then she figures out you lied she wont like that. so do what your heart says.
What I would suggest is that you become her friend but do not get into the friend zone, and do not try to act like someone you are not, and don't change for anyone. It is not worth it. Try to make her laugh, and do not be to clingy!