Cowgirl sex tips?

I’ve started having sex with this guy I’m seeing and he is always wanting me on top and I honestly feel like I’m shite? I feel so embarassed and shy and I can’t move my hips and get the rhythm right? I’ve looked up so many things on how to get my hips in better shape but I don’t know what specifically I need to do? Do any of you girls have any tips? Just want to give the man the time of his life and he’s not getting it😂😂 Xx