In Zephaniah 2:1-3, the people Zephaniah is talking to (that includes us!), need to change their ways and trust in the Lord and His Word.

In Zephaniah 2:4-7, there's a prophecy that the cities of the Philistines will come to grief and the whole area of the Mediterranean seacoast will be populated only by shepherds and their flocks, and these shepherds will be remnants from the kingdom of Judah. Here, the Philistines represent people who do evil.

In Zephaniah 2:8-10, the peoples who live around the land of Canaan, but not in it (the Moabites and Ammonites), stand for attitudes and evils that can cause temptations to good loves and true ideas. They are compared to Sodom and Gomorrah.

In Zephaniah 2:11... In the minds of people who wish to serve the Lord, those bad attitudes and evils must be destroyed, and with the Lord's help, they can be.

In Zephaniah 2:12-15, there are references to Ethiopia, Assyria, and Ninevah. When Ethiopia is referred to in a negative sense, it refers to people who use knowledges from the Word to confirm false ideas. Similarly, Assyria means reasoning from any knowledge which in this context leads to bad conclusions. And then there's Ninevah. This city means false doctrine, and these verses tell of her fate when judgement comes. Before that its people are proud of its learning, but after the Judgement, it is abandoned and empty.