Gen 1:20 And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.
The first heaven.
Deu 4:19 And lest thou lift up thine eyes unto heaven, and when thou seest the sun, and the moon, and the stars, even all the host of heaven, shouldest be driven to worship them, and serve them, which the LORD thy God hath divided unto all nations under the whole heaven.
Psa 8:3 When I consider thy heavens, the work of thy fingers, the moon and the stars, which thou hast ordained;
Eph 2:2 Wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience.
I would think this is the second heaven, or maybe it goes farther than what our eyes can see.
But it is probably the first heaven has to do with what pertains to this earth, the atmosphere, the clouds above us, and the second heaven has to do with things that do not pertain to this earth the sun, stars, with a different atmosphere, although the sun pertains to this earth to give light, and life by the sun affecting the earth.
Satan is the prince of the power of the air, and has access to the first and second heaven.
2Co 12:2 I knew a man in Christ above fourteen years ago, (whether in the body, I cannot tell; or whether out of the body, I cannot tell: God knoweth) such an one caught up to the third heaven.
2Co 12:3 And I knew such a man, (whether in the body, or out of the body, I cannot tell: God knoweth)
2Co 12:4 How that he was caught up into paradise, and heard unspeakable words, which it is not lawful for a man to utter.
2Co 12:5 Of such an one will I glory: yet of myself I will not glory, but in mine infirmities.
The third heaven where God dwells with the angels.
Some people think that Paul was speaking of himself.
He knew a man above 14 years ago, which sounds like Paul is speaking of someone else, and why would he be speaking of himself when of course he would know himself 14 years ago.
He did not know if the man was in the body or out of the body, which if it was Paul he would know, and also no flesh can dwell in the 3rd heaven but by the spirit, which John was caught up in the spirit to heaven and saw where God and the angels dwell.
Paul said he will glory in that man, but of himself he will not glory, so if it is Paul why the contradiction of saying he will glory in that man and then say he will not glory of himself.