After the rapture do non-Christians go to hell or into the tribulation? 

1 Thessalonians 4:14-5:3

What will happen in heaven during the tribulation period?

Revelation 6-19

What are the 7 seals, 7 trumpets, 7 signs and 7 bowls of Revelation? — The Tribulation

Revelation 6:1-19:19

Will people be saved during the tribulation?

Revelation 6:9-11

Does the rapture occur before the tribulation period?

Revelation 6:10-11; 7:3-4, 13-14