I'd suggest reading what she says in the front of the booklet. Basically, you look at the cards, read the meaning if you want, and listen to your intuition (i.e., any feelings and thoughts you have immediately after looking at the cards you drew).
You might find journalling helps you. Doesn't have to be lengthy. Just note down your question, the cards you drew, and your reaction or what you thought they meant at the time. Then later, go back to what you wrote and update it with what actually happened. Then you can see how the cards play out, how accurate they/your interpretations are, if you can make a connection in hindsight to something you experienced even if it was different from what you expected when you did the reading, etc.
You don't really need to gain any knowledge, I don't think. If you want to look up the goddesses in other sources, for example, that's up to you (and might be valuable!) but not required.
Tarot has a lot more structure to it than most other oracles and 'traditional' meanings associated with each card. If you were to get into tarot you'd probably want to study a bit, but some people don't. They take the same intuitive approach I'm describing here.
Just relax and have fun with them and keep using them. It'll come together over time.
Also, when you're using them for inspiration there really isn't anything to worry about. They inspire whatever they inspire, and that's that.
Hope that helps!