What did Jesus do between the resurrection and the ascension?
In the Gospel of Mark we have the angelic being (a young man in 16.5) informing the disciples that he will meet them in Galilee.
In the Gospel of Matthew Jesus greets the women himself commanding that they tell the other disciples that he will meet them in Galilee (28.10) confirming the message of the angel they met at the tomb (28.7). The disciples meet Jesus in Galilee and they worship him. Jesus informs them that he has received “all power in heaven and earth” and gives them what we call “the Great Commission” to make disciples of the nations (28.19). Then he informs them that he will be with them “even to the end of the age.”
In the Gospel of Luke Jesus appears to two men on the way to Emmaus. He explains how Messiah had to suffer as he did. He joins them for dinner, blesses the breaking of the bread, becomes apparent then disappears (24.13-35). At another point he randomly appears in the midst of the disciples offering them the opportunity to touch his wounds to see that it was him. Then he shared some fish with them (24.36-42). This is followed by another lesson about himself from Scripture with the promise of “power from on high.” (24.43-49) He leads them “as far as Bethany,” blesses them, and ascends into heaven (24.50-51).
In the Book of Acts the story continues with additional details: Jesus was present for forty days doing wonders and teaching about the Kingdom of God, he commanded that the disciples wait in Jerusalem until the promise arrives which he clarifies is the coming Spirit, he tells them that they will be his witnesses, and he ascends into heaven (1.1-9).
In the Gospel of John Jesus appears to Mary Magdalene. She thinks he is the gardener before he says her name and she recognizes him. She tries to cling to him but he says he must go to the Father (20.11-18). Jesus appears to his disciples randomly in a closed room and he offers the disciple Thomas the opportunity to verify his identity by touching his wounds (20.19-29). Our last scene with Jesus is on the shores of Galilee where he appears, tells the disciples how to catch fish, eats a meal with them, and has a long chat with the Apostle Peter about his future (chapter 21).
The Apostle Paul writes in 1 Corinthians 15.5-7 that Jesus was seen by Cephas (Peter), then the twelve, then five hundred disciples at once, then his brother James, then the rest who were called “apostles,” then to Paul himself “as one untimely born” which appears to have been after the ascension (at least the Book of Acts outlines it). This passage alone does not divide between Jesus’ appearances before the ascension and afterward, though Paul’s unique designation seems to imply that he saw his encounter with Jesus to be unique, so maybe this means the others saw Jesus before his ascension? In Galatians 2.9 he calls James, Cephas (Peter), and John “pillars” which may be further indication of their primary position as post-resurrection witnesses.
What similarities do we see? We find Jesus appearing to women first in all the Gospels, though the list of women are not exactly the same. We find Jesus being difficult to recognize on some occasions. Jesus can appear and disappear like a non-physical being though he eats food and he can be touched like a physical being. He invites people to see the wounds from his crucifixion indicating some sort of continuation between the body pre-resurrection and post-resurrection. He spends time with various groups, often in Galilee, and these visits seems to be “commissioning” like acts. He returns to God the Father in the Lukan and Johannine accounts, which the Pauline Epistles support elsewhere when speaking of his parousia as do the Johannine Epistles when addressing his “appearing.” In the Catholic Epistles (e.g. 2 Peter 3.1-9) this return seems to have become a central doctrine and a return indicates a departure.
Each story contains unique elements. Some things seem assumed (e.g. Luke-Acts is the only work that details the ascension). Overall we are told of a Jesus who is very much like his pre-resurrection self (eating, being touched, scares from wounds) yet very different (hard to recognize, appearing and disappearing, endowed with exceptional power and authority, able to transition into the heavens).
the archives near Emmaus 
I often wonder where is Jesus now? Obviously ascended and sitting at God’s right hand? But where is that?
It appears that he dwells physically in the realm of heaven, which is quite an interesting picture if you ask me! I know that many theologians speak of heaven and earth meeting in his person or in Christ creation being brought into the realm of heaven/married with the realm of heaven (e.g. Rev. 21). So he seems to be the first “physical one” to be able to be in both worlds.