Learn German: Mia steht gern im Mittelpunkt. Dagegen mag ich keine Aufmerksamkeit. - Mia likes standing in the center. On the other hand, I do not like attention.

Dagegen (on the other hand) is an adverbial connector that takes up the first position in this sentence. Because German requires the conjugated verb to be in the second position, mag comes immediately after it, pushing the subject ich to the third position.

Could I put Dagegen somewhere else in the sentence?

Yes! Adverbial connectors like dagegen are flexible. You could also put the subject first and say Ich mag dagegen keine Aufmerksamkeit. The verb mag still strictly stays in the second position.

What does im Mittelpunkt stehen mean literally?

It literally translates to standing in the center point. In German, this is the standard idiom to express being the center of attention.

Why do we use keine instead of nicht to negate the second sentence?

We use keine because we are directly negating a noun without an article (Aufmerksamkeit). If we wanted to negate a verb, an adjective, or a noun with a definite article, we would use nicht.