id say start simple, try tying him up, blindfolding and then just give him a massage (dont forget the intimate parts hehe). Simply start out having fun! No need to bring out a ton of tools, use your hands and feets! also you could simply order him to kneel before you, and then walk around him enjoying the sight. Or simply order him to touch you at certain places you enjoy a lot.

Id say that the thing about dominating one for the first time really is about answering the question: what do i like? what makes me feal good? when these have been answered, talk about it with the sub to become. Now these things can be as simple as: i like it when he kisses me there, or i like it when he looks up at me when he does... etc. And then there is only the last topic: doing it!

Also remember, its allright to say: this isnt really me can we try something else? remember this is supposed to be an good time, take it slow have fun and enjoy each others bodies as much as possible