Christians and the distinction between "Moral", "Ceremonial", and "Judicial" laws.

So I recently watched a video about how Christians who think homosexuality is wrong, but don't abstain from wearing mixed fabrics or eating shellfish, aren't hypocrites because modern Christians are only supposed to follow the moral laws, but not the ceremonial or judicial laws found in the Bible.

I think the logical conclusion to this is to ask: "Okay, so if there is this threefold distinction, can we have an exhaustive classification for what laws in the Bible fit into which categories, so we can know which to discard?". When I asked this question, I was given several answers, majorly that "Christianity isn't about following a set of rules, but walking with Christ".

And so I'm like... does the rulebook scripture-quoting thing only apply when it's something that you personally dislike a lot, or what? Because that seems to me to be a lot like picking and choosing—or rather, that it serves to act as a system for one to arbitrarily say that a law/commandment fits in one of the 2 irrelevant categories on the fly, rather than actually taking the laws and sorting them objectively based on what categories they fit into. Any thoughts on this?