"I dag har jeg to prøver."

Nothing, it's just not US EN.

In Danish (and in German too) the verb often comes as the second element in the sentence. The first element is the one on which you want to put the focus (it can be the subject, but also a complement, leading to a complement - verb - subject sentence).

Here, the focus of the phrase is on "i dag" (today). Even though it's made of two words, it counts for one lexical entity. Then comes the verb in the second position, and the subject afterwards.