how do i talk to this girl in my gym class?

[sk8boarder5004]

there is this one hot girl in my gym class that i kind of like and i think she may like me a little too. but sometimes i just dont know what to say and how to start up a conversation. she is easy to talk to though but it is still hard sometimes. and how can i tell if she likes me, her body movements, speech, etc. any tips