Hey @raquelg,
A warm welcome to the community!
Advanced Pricing Rules can be challenging, but it's great that you're taking the initiative to reach out. There's a brief overview guide available from QuickBooks Learn and Support.
Hector Garcia is a QuickBooks Pro and makes amazing video content. I watched his video on QuickBooks Enterprise Price Rules a few months ago to get the basics. There's some information about applying conflicting rules around (7:29).
Let me know if this helps, happy New Year.
