Learn Dutch: Je wordt rustig door elke melding uit te zetten. - You become calm by turning off every notification.

In English, we express this idea using "by" followed by an "-ing" verb ("by turning"). Dutch doesn't use "-ing" forms this way. Instead, to say "by doing something", Dutch uses the preposition door at the start of the clause, and puts te + the infinitive verb at the very end.

Why is te placed in the middle of uitzetten?

Uitzetten (to turn off) is a separable verb, made of the prefix uit and the root verb zetten. When you use a separable verb with te, the te must go exactly between the prefix and the verb. Notice that they are written as three separate words: uit te zetten.

Why does elke have an -e at the end here?

The noun melding (notification) is a de-word (de melding). When you use the word elk (each/every) with a singular de-word, it gets an -e ending to become elke. If it were a het-word, it would remain elk (for example, elk bericht - every message).

Does je in this sentence refer to me specifically, or people in general?