Yes, I totally understand what you mean, because prepositions are the hardest topic in most languages, including Italian, and that’s because there aren’t always rules. You just need to memorize which preposition goes with each word/phrase. That’s precisely why I include an exercise about preposition in all of my activities (podcasts, videos, etc.). This way you can learn through the solutions and practice by taking the same test again or a new one.
There are a few rules, though, and I explained them in my online courses (for example here).
If you need help with prepositions, you can leave more comments here or we can talk about it in the #grammar channel on Discord. 🙂