Learn Danish: Vi står op tidligt.

In the context of mornings, står op is the standard way to say get up. It literally translates to stand up, but it functions just like the English phrase to describe getting out of bed.

Why does the word for early, tidligt, end with a -t here?

The dictionary form of the word early is tidlig. When you use it to describe an action like står op instead of a noun, it becomes an adverb. In Danish, you usually add a -t to an adjective to turn it into an adverb.

What is the difference between står op and vågner?

Vågner means to wake up, meaning you just open your eyes and become conscious. Står op specifically means you physically get out of bed to start your day.