What's the structure for next week?

The English phrase "next week" is an adverbial of time, which consists of the adjective "next" and the noun "week", meaning "next week". It is used in the simple future tense and is usually used with will or going to.

We will go for a spring outing next week. We will go for a spring outing next week.

Please note that when used in a sentence, next week cannot be preceded by a preposition.