The scriptures don’t have much to say about exactly what was going on during the day following Jesus’ death. However, we do know that it was the Sabbath (Luke 23: 50-56), so no work was allowed. But according to Matthew’s gospel, (27: 62-66) we know that the chief priests were worried about people coming to steal Jesus’ body to claim He had been raised, so they asked Pilate to post a guard, which he allowed.
We could speculate on what the disciples were doing, but my best guess is that it was a mix of cowering in fear, combined with reconciliation of the shock of what they had seen and heard the day before along with a potent amount of pure grief. And perhaps some lingering anguish over their own conduct.
However, I contend that at a soul level, Christ was at work, and for this day, I will simply link back to an article I wrote earlier this year on my contention that Christ descended into hell.