Learn Italian: Non mi piace il formaggio.

In Italian, the verb piacere doesn't exactly mean "to like"—it actually means "to be pleasing to." Instead of saying "I like cheese," you are literally saying "The cheese is not pleasing to me." Because the singular noun il formaggio is the thing doing the pleasing, the verb takes the "he/she/it" form: piace.

Why is there an il before formaggio? English just says "I don't like cheese."

In Italian, when you talk about a broad category or something in general (like cheese as a whole concept), you must use a definite article like il or la. Even though we drop "the" in English, you have to include it in Italian.

How does the word order work with non and mi?

When you want to say you do not like something, the negative word non goes right before the pronoun mi. You simply put non at the very front of the phrase to create non mi piace.