Three appearances are written in Mark, but after each one there is unbelief. Jesus appeared to Mary Magdelene. Jesus appeared to two disciples walking in the country. Jesus appeared to the eleven disciples while they were eating. Jesus said if a person does not believe, that person is condemned.
Baptism goes along with belief.
While a person does not have to be baptized to be saved, saved people should want to obey Jesus and be baptized. Jesus said his disciples would perform miracles. This happened in the book of Acts. Jesus was taken up to heaven and sat at the right hand of God. He is the first human being in the Bible recorded as being there, and he will take believers to be with him there when we die to await our own resurrection.