I'm useless

Ok so my bf usually takes control in the bedroom and I love it but I feel like I want to just once to kinda surprise him but I get embarrass and scared that I'll fuck it up 😂 and I really want to try to have sex but I swear to god I'm to small and I know it's like impossible but I've tried and legit nothing will fit!!!! so I just end up sucking his dick but I wanna change it up a bit any suggestions?