Learn Italian: Non voglio vedere né il cameriere né il cuoco. - I want to see neither the waiter nor the cook.

In Italian, when negative words like né... né... (neither... nor...) come after the verb (voglio vedere), you must still put non before the main verb. Unlike in English, this kind of double negative is completely normal and required in Italian!

Why is there an accent mark on né?

The accent mark is there to distinguish it from ne without an accent, which is a completely different word (a pronoun meaning "of it" or "some of it" that you might remember from earlier lessons). The accent tells you it is the word meaning "neither" or "nor".

Why is vedere in its infinitive (dictionary) form instead of being conjugated?

Because it comes right after the conjugated modal verb voglio (I want). When you pair these verbs together to say what you want to do, the second verb stays in the infinitive, just like the English "to see".

Do we always have to use a definite article like il right after né?

No, né doesn't force you to use an article. You simply use whatever article the noun normally needs. Here, we mean "the waiter" and "the cook", so we need il. If you were saying "neither meat nor fish" in a general sense, you could just say né carne né pesce without articles.