Jews, can you teach me the most important precepts of the Torah?

Torah, Pentatauch, Chumash, just the Five Book of Moses. I know many jews and rabbis study the Law of Moses most diligently. I have a hard time understanding it, because a good portion of it has ceremonies, rituals, sacrafices, misc. things that don't relate to me and my life, unless I am wrong. And the Ten Commandments too. So...