Ideas?

My girlfriend(24) and I(28) are exploring the side of the dom and sub stuff. I was wondering at what things we can lean into as we really dont know where to start.

We have established that she likes being called "good girl" and possibly getting a punishment for not doing what I say. We also like the idea of her being able to be fucked when I feel like it, kinda like free use but with boundaries set.

What other ideas can I throw out there to see if we would be keen to try. Were just fresh on this and want to explore it.