Qualifications to answer from this perspective: I am a nontrinitarian Christian, monotheist, who believes John 17:3 which teaches that the Father is "the only true God." I also accept that Jesus was a man with flesh and bones (see Luke 24:39) who was possessed by God (see 2 Corinthians 5:19; Proverbs 8:22-31; Hebrews 10:5; John 14:10).
Answer: Jesus was dead from the time of his expiration on the cross to his resurrection, and did not "do" anything nor "go" anywhere. His lifeless body was, of course, removed from the cross and placed in the sepulchre, but of this he would have known nothing (see Ecclesiastes 9:5-6).
During his life, Jesus taught repeatedly that the words he spoke were not his own words, but those of the Father. This is important to understand with relationship to his death because of the prophecy which he had given that...
... Destroy this temple, and in three days I will raise it up. (John 2:19,
That those were the Father's words is made clear from Acts 13:30:
But God raised him from the dead: (Acts 13:30, KJV)
Jesus, being dead and knowing nothing, could not possibly have raised himself. It was God (the Father) who raised him from the dead, just as it had been the words of the Father which he had spoken regarding his temple.
Jesus confirms the fact that from the time of his death until his resurrection he had not gone to heaven.
13And they say unto her, Woman, why weepest thou? She saith
unto them, Because they have taken away my LORD, and I know not where
they have laid him. 14And when she had thus said, she
turned herself back, and saw Jesus standing, and knew not that it was
Jesus. 15Jesus saith unto her, Woman, why weepest thou?
whom seekest thou? She, supposing him to be the gardener, saith unto
him, Sir, if thou have borne him hence, tell me where thou hast laid
him, and I will take him away. 16Jesus saith unto her,
Mary. She turned herself, and saith unto him, Rabboni; which is to
say, Master. 17Jesus saith unto her, Touch me not; for I am
not yet ascended to my Father: but go to my brethren, and say unto
them, I ascend unto my Father, and your Father; and to my God, and
your God. (John 20:13-17, KJV)
Following his resurrection, Jesus briefly departed to heaven, as he tells Mary, before returning to earth and meeting with the disciples, spending some days with them again before returning to heaven. But all of this happens after he was raised to life; none of this happened between his death and his resurrection.