How can I communicate what feels good to my boyfriend if I dont know myself

My (17F) boyfriend (18M) and I are trying to work towards sex with hand stuff and oral, but I can never properly explain what exactly I want or what feels good to him because I have no idea what he needs to do to make me feel good. It‘s just so different from when I pleasure myself, so I never know what to say and that results in me just not feeling anything from what he does.