Learn German: Lesen Sie die Warnung und klicken Sie nicht auf den Link! - Read the warning and do not click on the link!

No, these are formal commands (the imperative). When giving an instruction to someone you address with the formal Sie, the verb is placed at the very beginning of the clause, followed immediately by Sie.

Why does the sentence use auf den Link (accusative) instead of auf dem Link (dative)?

The verb klicken is used with the two-way preposition auf. Clicking is treated as a directed action toward a target (clicking onto the link), which triggers the accusative case. Since Link is a masculine loanword (der Link), the article becomes den.

Why is nicht placed right before auf den Link?

In German commands, the verb and subject pronoun (klicken Sie) must stay at the start. The word nicht typically comes after them, and it is placed directly in front of the specific element it is negating, which in this case is the prepositional phrase auf den Link.

This lesson focuses on sonst (otherwise). How would I naturally continue this warning using sonst?