The four men Jesus called to follow him that day were two sets of brothers, Simon Peter and Andrew, and James and John. Three of these Jesus had met about a year earlier and he had probably spent a good deal of time with them over that period. John and Andrew were the two followers of John the Baptist, who had pointed Jesus out to them after Jesus came out of the wilderness. Andrew fetched his brother Simon and they spent the rest of the day with Jesus. (Read John 1:35-51.) James is never mentioned as being there, one of the few times in the Gospels where James and John aren't mentioned together. Perhaps James had stayed home to tend the business. Probably John filled him in when he got home and both brothers spoke with and traveled with Jesus during the coming year.
It was in Bethany at this same time that Jesus met Philip of Bethsaida and Nathanael Bartholomew of Cana. We do not know what Philip and Nathanael Bartholomew did for a living. Bartholomew is the Greek for the Aramaic "bar Tolomy", so his name was Nathanael son of Tolmay. Tolmay might have been his father's name. Tolmay also translates as "furrows; thus Bartholomew can be "son of the furrows", thus his occupation might have been farming. We know he was from Cana from later Scripture, after Christ's resurrection when Jesus meets five Apostles along the sea. These four are listed (John 21) as the two sons of Zebedee (James and John), Nathanael of Cana in Galilee and two others. One of the others is quickly revealed to be Simon Peter. The other is not identified. Perhaps it was Peter's brother Andrew or maybe it was Philip. Nathanael and Philip seemed to be close friends.
It is very likely these four men had traveled to Bethany together to be with John the Baptist. It is plain from the text they were seeking the Messiah, so they had a common purpose. This also indicates these were devout Jews who knew Scripture and prophesy. They knew the time was ripe for the appearance of the Messiah. Philip lived in Bethsaida and so did John and Peter. Nathanial lived not far away in Cana.
When these four (assuming James was not there with John) accompanied Jesus back to Galilee, their first stop was at a wedding in Cana. Some have even speculated this was the marriage of Nathanael, but that would not fit the wedding customs of those times. Most likely they went to the wedding because Jesus was invited. His mother was involved in it. It was convenient to leave Nathanael there in his home town.
(You can read the full story of these meetings and early travels with Jesus in my Companion.)
So, to recap, before this so-called calling of the Apostles, Jesus had already befriended and spent time teaching six of them: Simon Peter, Andrew, James, John, Philip and Nathaneal Bartholomew. On the day along the seashore when he said, "Follow me and I will make you fishers of me," it was to the first four in this group. These four are always listed first in the listings of the twelve, with Peter always at the top. We hear more about these four throughout the Gospels than any of the others, although not as much of Andrew as the other three. Even so, there are passages indicating Andrew was included is private conversations between Jesus and this group.
As Jesus was sitting on the Mount of Olives opposite the temple, Peter, James, John and Andrew asked him privately, “Tell us, when will these things happen? And what will be the sign that they are all about to be fulfilled?” Mark 13:3-4
Andrew may have been something of a gatekeeper at the top. He would interact between others.
The second group that are always named together are Philip, Nathanael Bartholomew, Matthew and Thomas, with Philip always listed first. If the first group are the heros, the stars, these are those who get a scene or two in the limelight throughout the Gospels. Like the four stars, two of these fellows knew Jesus from the time he had been Baptized by John and returned from the wilderness. When Jesus actually called them to follow on his ministries, we do not know. It may not have been long after he called the first four off their boats.
The only other of the Apostles where we have information about him being met by Jesus and called is Matthew Levi. Jesus had come off a boat into Capernaum, where he was living then, he stopped by a paralyzed man and had a confrontation with some teachers of the law. After curing the man, Jesus went on into town and saw this tax collector at his collection booth. He called to this man to follow him and the man did. His name was Matthew (also Levi). Right after this Jesus has dinner at Matthew's home along with other tax collectors. Here he has a confrontation with the Pharisees over the company he keeps.
This is all we know about any of the "callings" of the Apostles.
The last member of this middle group is Thomas, known as Doubting Thomas to most and also known as Didymus, which is the Greek for Thomas. The name means "The Twin". We don't know if Thomas was actually a twin or not. We also don't know where Thomas was from, what he did for a living, where he met Jesus or how he was called.
The last group I haven't called The Obscurity for nothing. About all we know of these, with the exception of Judas Iscariot, is the names. They appear in the lists of the twelve, always with James son of Alphaeus listed first. We do not know when Jesus met or called these people.
It would seem it was in proximity of when he called the others. It is not that far into his first Galilean ministry when he calls them together and selects them as Apostles.
So you see, the calling of the Apostles is a bit more complex than usually presented in pop culture. In fact, even the term of Apostle is misunderstood. First these men were disciples, along with perhaps many other people. A disciple is a student, someone learning from the teacher. When Jesus called Peter, Andrew, James and John to follow they did so as disciples. After some time went by, Jesus called a number of his disciples to a private place on a mount and there he select twelve to be Apostles. Although Apostles may continue being disciples, that is still learning, disciples aren't necessarily Apostles. Apostles are Messengers, people capable to taking the message to others and teaching others to be disciples. These men were called to be disciples, they were selected to be Apostles.