What should a girl do with her hands when making out with a guy?

So I've been hooking up with this guy (just making out) & like we make out outside & in his car & a lot like whenever we see eachother & its really fun. he's 17 & im 15 but like we have a lot of fun together. i snuck out of my house a few times to make out w/ him on my side yard & the last time we laid out a blanket & made out w/ eachother on top of eachother. but now i get confused what to do with my hands. like if hes on top or on the bottom idk what to do with my hands his are usually on my but & holdin up my head but i get so confused... help me!