Here's what I've heard you say.

You're inexperienced.
He's inexperienced.
You want to be dominated but it's about a feeling and you aren't sure what or how to ask. That's okay, you're inexperienced.
You're concerned about pressuring him. That's okay too.
He's unsure about what you want because you're both inexperienced.

All the advice about open communication is great and correct... but you're both inexperienced, you don't know what to talk about.

You can do a lot of self-education, and get a lot of advice online to boot, but the bottom line is you're trying to do this in isolation.

You need a mentor. Male or female, sub or dom/me, doesn't matter. Online is doable but as you are in a "real life'/in-the-flesh/face-to-face relationship, an in-the-flesh mentor would be preferable.

I suggest you and your partner find a local munch group and attend together, find a women's group or a sub group for yourself, and start talking, listening and learning. Find someone you find sympathetic and willing to assist/mentor you.

If you're lucky, you can find someone both of you can relate to.
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One more thing. As tessa and Mr. F point out, you are very young with a lot of life ahead of you. There is NO rush. Anything you decide while you still live at home is likely to undergo an evolution of thought once you're on your own. If you perceive college in your future, the time spent there will be different yet, from both before and after college.

Take your time and enjoy the journey.