でございます is a super-polite version of です. It is used in formal situations like business meetings, public announcements, or when speaking to customers. You will hear it in department stores, hotels, and on trains. It is not used in casual conversation with friends—it would sound oddly stiff and distant.

When you use it, attach it directly to a noun or な-adjective stem: 私でございます, 結構でございます. For い-adjectives, the adjective changes to its く-form first: よろしい → よろしゅうございます (note the sound change). But for N4, focus on nouns and な-adjectives.

Note that でございます is the same politeness level as です but more formal. In modern speech, it is often replaced by であります in written formal Japanese, but in spoken polite service, でございます is standard.