Learn Spanish (Latin America): El turista está perdido en la ciudad.

In Spanish, the adjective perdido changes meaning depending on the verb you use it with. Estar perdido means to be physically lost or confused, which fits this tourist perfectly. If you use ser, as in ser un perdido, it means someone is a 'lost cause' or a person with bad morals!

Since the tourist is masculine here, why doesn't the word change to turisto?

Words that describe professions or types of people and end in -ista (like turista, dentista, or artista) are used for both men and women without changing the ending. Because this tourist is male, we just use the masculine article el to show the gender.

If the tourist were female, what else would change in this sentence?

The article would change to la, making her la turista. Also, because adjectives must match the noun's gender, the adjective changes to perdida. The whole sentence would be: La turista está perdida en la ciudad.