Learn Italian: Nessun artista lavora qui.

Words ending in -ista like artista have the exact same form for both masculine and feminine in the singular. We can tell this is grammatically masculine because it uses nessun without an apostrophe. If it referred specifically to a female artist, it would be nessun'artista (short for nessuna). Here, the masculine is used as the default to mean 'no artist in general'.

Why do we use nessun instead of nessuno?

Nessuno drops its final -o (becoming nessun) before masculine singular nouns that start with a vowel or most consonants. Since artista starts with a vowel and is treated as masculine here, we use nessun artista.

Don't negative sentences in Italian usually need non?

Usually, yes! But when a negative word like nessuno (no/nobody), mai (never), or niente (nothing) comes right before the verb, you must drop the non. If you flipped the sentence order, you would need the double negative: Non lavora qui nessun artista.

How would I say 'No artists work here' in the plural?