Two Marys
According to Matthew, Mary Magdalene and another Mary were the first to find out that Jesus had risen. And then they saw him, before they got a chance to tell the disciples what they’d heard. So none of the disciples even heard that Jesus was alive before the Marys saw him. And I think we can assume they hadn’t independently seen him yet either, or the angel wouldn’t have told the Marys to tell the disciples that Jesus was alive.
One Mary
According to Mark, Jesus appeared to Mary Magdalene first. It doesn’t mention any other Mary. And it says when she told the others that Jesus was alive, they didn’t believe her. So that’s further confirmation that no one else had seen him yet.
John agrees with Mark that Mary Magdalene was the first to see the resurrected Jesus. John also says that when Jesus first appeared to some of his disciples after the resurrection, it was to ten of them at once.1
Two disciples
According to Luke, some women found out that Jesus was alive, but didn’t see him (which disagrees with Matthew and Mark). The women told the disciples, who didn’t believe them. Then Peter went to look at the tomb himself, but he didn’t see Jesus either, and he wasn’t sure what had happened to Jesus. So at this point, no one has seen Jesus alive yet.
Then it says Jesus appeared to two disciples, who were seven miles away from the others at the time. When they got back to Jerusalem, they told the other disciples about it. Then Jesus appeared to all the disciples there, and they were shocked, because the disciples in Jerusalem hadn’t seen him alive yet. So when some of the disciples first saw Jesus resurrected, it was only two of them, not ten, contrary to John.
Just Peter
And according to Paul, the risen Jesus appeared to Cephas (Peter) before he appeared to the rest of the disciples. (Again, no mention of Mary.) None of the gospels agree with Paul that Peter was the first to see Jesus. Except maybe the gospel of Luke? It says when those two disciples told the others they’d seen Jesus, they also mentioned that Jesus had appeared to Simon (Peter). Even though Luke had already specifically mentioned Peter not seeing Jesus.