Mormons use this verse to explain their three kingdoms of heaven, which they call the celestial, terrestrial, and telestial kingdoms. According to this view, everyone who dies will eventually make it to one of these three kingdoms.
However, Paul was merely explaining how he ascended (probably in a visionary state) into the presence of the Lord. The “first heaven” is the earth’s atmosphere. The “second heaven” is made up of the stars and outer space. The “third heaven” is the presence of God.
Another verse used by Mormons to support the idea of three heavens is 1 Cor 15:40, but this only explains the difference between heaven (“celestial”) and earth (“terrestrial”). A third “telestial” kingdom is never mentioned.
Meanwhile, those who believe in the separation of the body and soul along with the possibility of soul travel have claimed that this verse supports this idea of astral projection. But Paul said this was an unexpected “vision.” It is not something he purposely set out to experience.