After this life, we go to spirit prison that has two divisions, Paradise and Hell. Both resting places will receive further instruction of the true gospel from missionaries sent by Jesus. Jesus went to preach to the spirits in prison. While he may have, he set up the missionary organization to carry on this work. 1Peter 3:19-20 and 1Peter 4:5-6. If one in Hell truly accepts the gospel in spirit prison, they will be moved to Paradise to await the judgment and resurrection. After the resurrection, we are assigned what we sowed. There are 3 types of resurrected bodies in Heaven. Celestial (the Sun), Terrestrial (the Moon) and Telestial (the Stars) One brighter in glory than the other. 1Cor. 15:39-42
As far as what the requirements are to obtain the highest degree of glory, the Celestial Glory, the Lord shall mediate with the Father in our behalf for that is what the atonement is all about. One ordinance for sure is required. That is the ordinance of baptism by one who has authority to baptize. But, what about those who are dead? Paul was strongly opposed to use false analogies or teachings to teach the truth. So, in 1Cor. 15:29, the people were righteously instructed to baptize for those who have died. They do this vicariously through proxy. This way, generations of ancestors could be baptized if families kept genealogical records as we in our Church do today in our Temples. In one of our book of scriptures, The Doctrine and Covenants" for instruction today in these the latter days, Section 76 covers in more detail what it takes to receive each of the 3 degrees of glory. We are also taught that there is more than one level in the Celestial Kingdom. To receive the highest in that kingdom, one must be sealed to a person of the opposite birth sex for all eternity.