The first thing that you have to ask is what proof do we have that Jesus really died? Crucifixion was a method of execution that sometimes took days to complete. That was the point of the whole extravaganza. The culprit was punished and a sign hung above his head telling how he got himself into such a predicament and the execution site was always where people could easily and readily see it. It was a test of strength with the criminal always loosing in the end. With the arms extended and the feet nailed down with the knees pushed slightly up allowed the unfortunate to breathe. He could breathe as long as he kept his arms straight. This meant he had to hold his entire weight up and he would do this until little by little the burning pain in his arms made him slowly lower himself. When he reached the bottom, he realized that he could not breathe and so pushing painfully on his nailed feet he once again pulled himself up. This would go on until his strength gave out and he could pull himself up no more. For a strong man, this could take a couple of days. This is why Pilate was so surprised to hear that Jesus was already dead after only a few hours. Now, keep in mind that Jesus had been scourged, that is whipped with a whip that had bone sewed into the ends of thongs and blood was drawn each time a blow landed. He would have lost a lot of blood because of this procedure which was not a normal part of the crucifixion process. Normally you were scourged and then released. You may have died later due to infection, but that was not the Roman’s concern. Jesus also, like all of the criminals, had to carry the cross member called the patibulum for His cross and that weighed between seventy-five and one-hundred-twenty-five pounds. Consider that he was doing this while in shock from loss of blood and very likely had not eaten or drunk anything since the previous night so that weakness from hunger and dehydration was most likely setting in and you can see that this was not a man in possession of his full strength. Also, there is some speculation that when Jesus fell the first time, the fall caused some internal bleeding that further weakened him. He was so weak that his escort was afraid that he might die on the way to his execution. That would be bad for them because they were charged with seeing the criminals die on the crosses that had been prepared for them so they arranged for some help from a stranger picked from the crowd to help Him. So by the time Jesus was actually nailed to the tree, I would think that He was a terminal case already, nothing, save a miracle, could save Him. So after a while His strength gave out and He died. The other two men crucified on either side of him were still fat and happy and they did the crucifix shuffle for the crowd. The Romans were taking no chances. Jesus just may have been faking. To forestall any thought of that, a roman pierced his body, going into the Heart and blood and water flowed out. So I have no doubt that Jesus was dead and the manner of His death was homicide by legal crucifixion.
What did Jesus do after He died? I think we have established that this was not some phony scheme thought up thy Him and his disciples to fool the Romans and the Temple gang. When Adam and Eve sinned, they in effect saw to it that the gates of heaven were closed to themselves and all of there descendants. That is why Jesus came, to redeem us and to bring us back into fellowship with God the Father. So, from the time of Adam to that Good Friday all people were barred from heaven, so where did they go? The place that they went has two names and they are Sheol and Hades. Both of the names refer to the exact same place. Jesus went to Sheol and told the just souls that were there that their wait was over and that they could now enter the Heaven that was now ready to receive them. The unjust who were also in Sheol but in a place of torment (remember the story of Lazarus and rich man) and they were sent to the place of damnation or as we call it, hell.
The death of Christ on the Cross is the first part of the story, the grand finale is Easter Sunday, the day death died.