If you remember your linear algebra basics, you could easily pick up QM --- the parts that deal with finite size systems. Here is an excerpt from my book I posted a while back in another thread, and refreshed today since you asked: https://minireference.com/static/excerpts/noBSLA_quantum_cha...
As for the multiverse, I don't know enough to talk about it. I just know it's one of the possible interpretations of quantum mechanics. Note that the various interpretations are generally considered more philosophy than science, and have no (or very little) practical implications. I would suggest ignoring all analogies and not looking too deeply for interpretations, and instead focus on basic concepts like "What is a quantum state?" and "How do I compute measurement outcomes?" which are super well understood and the same under all interpretations.
You can think of the various interpretations of QM as different software methodologies, scrum, agile, waterfall, etc. just stuff people like talk about endlessly, but ultimately irrelevant to the code that will run in the end.
As for the multiverse, I don't know enough to talk about it. I just know it's one of the possible interpretations of quantum mechanics. Note that the various interpretations are generally considered more philosophy than science, and have no (or very little) practical implications. I would suggest ignoring all analogies and not looking too deeply for interpretations, and instead focus on basic concepts like "What is a quantum state?" and "How do I compute measurement outcomes?" which are super well understood and the same under all interpretations.
You can think of the various interpretations of QM as different software methodologies, scrum, agile, waterfall, etc. just stuff people like talk about endlessly, but ultimately irrelevant to the code that will run in the end.