This is actually an interesting question, which probably deserves it own thread.
It’s common for Christians to divide OT laws into moral, ceremonial and municipal law. I think that’s good theology, but it’s bad exegesis. It’s good theology, because obviously the NT doesn’t accept all OT laws as valid. (Food laws seem to be explicitly rejected, e.g.) But it’s bad exegesis, because there’s no sign of that division in the OT itself. Lev 20:22-23 seems to apply to the whole Holiness code. It sees that code as what distinguishes Israel from the nations. That would include the food laws. Violation of food laws would cause Israel to be vomited from the land just as much as violation of sexual rules.
In the NT, of course, the relationship between the OT and Christianity became a serious issue. No one that I know proposed the usual three-way division.
Acts 15 summarized rules, but that seems to be a variant of a Jewish tradition that based laws for non-Jews on the Noah story. (As often, that involved some creative interpretation by the rabbis.) The reason Jews used that approach is that the Law is part of the covenant, and that doesn’t apply to Gentiles. The things God told Noah to do, however apply to all of humanity. However not everyone agrees that this is where the list came from, and in any case the list seemed to focus mostly on issues that might separate Jewish Christians from Gentiles Christians. It's possible that it isn't a complete list of ethical principles.
I think there are some signs that Jesus saw the 10 commandments as the most important moral principles.
Paul seems not to see the Law as binding. He suggests it in some general sense as a guide, but apparently not all of it. He doesn’t say how to choose. His sin lists (1 Cor 6:9 and Gal 5:21) don’t seem to correlate with any particular Biblical list.
But nowhere do I see an attempt to divide up the Leviticus code, or OT Law as a whole, into pieces that apply and those that don’t. I would say that the whole thing doesn’t apply.
Personally, I base my ethics on Jesus’ teachings, plus lots of Christian experience of the consequences of various types of behavior, though I’d accept the 10 commandments as part of ethics. Not as the whole contents, though. Example of things that come from experience are the prohibition of slavery, and modern concepts of informed consent in sexual matters. (Even conservative Christians accept many applications of this principle, e.g. prohibiting sex with a minor.)
