I suggest the book, "Leading and Supportive Love" by Chris M. Lyon, it's a good overview and explanation of the two positions, what they are and what they desire, and what they look for in a relationship/partner. It's a little more focused on the relationship side, not really kink, but it's the book that helped my husband to learn he was a submissive, and to better understand his wants and desires, and helped me learn I'm Dominant, and understand my love further in the process.
Other than that, the test Amar is a good baseline but kinda as she said, it's not an end-all-be-all. I mean, I've taken it several times, and depending on my mood my results change. Plus, to me, it's just a bedroom thing. And BDSM (can be/) is more than just the bedroom. I like to bottom sometimes in bed, I dont like submitting on a daily basis though. Itll be a help in figuring out what kink aspects to look into further, though. If you score high in something, start reading topics here on it, ask questions, Google, find books (I scour Amazon's marketplace a lot and get things on my kindle app on my phone. I'd prefer hardcover but, living overseas right now, it takes forever to ship to me haha).
And of course, ask questions here! I would make sure it hasn't been asked already first, but most here are pretty helpful so dont hesitate to post a forum topic like you did here, to ask more specific questions:) I'm new myself (Known about it for 5 years, only actively been a Domme for 5 months), but I have learned a lot pretty quickly, thanks to my love having been a submissive for 19 or so years (before he knew it even). So, feel free to reach out to me with questions if you wish

My inbox is open, if something is a little more private.
And of course, welcome to the community!