There is a lot we do not know about what happens then.
We could not meet God right when we die, unless we go straight to heaven. Seeing God is the greatest joy in heaven.
I presume most of the just go to purgatory rather than heaven when they die. According to the Catholic understanding, no one can approach God or see God with even one sin on his soul. In purgatory souls are cleansed of all sins.
That there is a real fire in hell, is part of Catholic doctrine. (The Catechism of the Catholic Church, in section 1035, says it is a place of "eternal fire") Furthermore, Jesus said of a lost soul, better if he had never existed. It would have been better because he will exist forver in the inferno. The fact that every soul ends in heaven or hell, and exists forever, is part and parcel of Catholic belief.
There are people who have died and been brought back to life. If this can happen at all, it seems that souls remain with their bodies for some minutes after they die, or they could not be brought back to life by natural means.
I sometimes have wondered what Lazarus told people about what happened after he died (after, naturally, they asked him about it), after Jesus raised him back to life after he had been dead for three days. But some people after they died, so accounts say, saw a great light which they began approaching before they were brought back to life.
But we don't know much about what happens then. But of course, we will all find out what happens then.