Learn Dutch: Ergens staat de auto. - Somewhere, the car is parked.

This is because the sentence starts with Ergens (somewhere). In Dutch, the verb must be the second piece of information in a standard sentence. When you move a word like Ergens to the front for emphasis, the subject (de auto) and the verb (staat) have to swap places so the verb stays in the second spot. This is called inversion.

The English translation says 'is parked', but doesn't staat mean 'stands'?

Exactly! In Dutch, it is much more natural to use posture verbs like staan (to stand) or liggen (to lie) to describe where things are located, rather than just using zijn (to be). Because a car rests upright on its wheels, the Dutch say it stands somewhere, which translates well to 'is parked' in English.

How would I say this without using the inverted word order?

You would put the subject first: De auto staat ergens. This is the neutral way to say that the car is somewhere. Starting with Ergens just puts a bit more focus on the location itself.

I have seen the word nergens before. How does it relate to ergens?

Ergens means somewhere. If you add an 'n' to the beginning, you get nergens, which means nowhere. Both are very common location words that will trigger this flipped word order if you put them at the start of your sentence.