When the Savior visited the people on the American continent, He immediately helped organize the Church there.
He called 12 disciples to lead His Church in that land. Then He taught them how to baptize people. They knew something about baptism already (see Mosiah 18), but it seems like there were still questions about exactly how it should be done.
“And there shall be no disputations among you, as there have hitherto been,” the Savior said.
Out of all of the things the Savior could’ve taught first, why do you think He started with baptism?
Maybe because He knew that the power that comes with baptism—including the gift of the Holy Ghost—is one that could comfort and guide the people in an ongoing way, whatever they faced going forward! It helps us in this life and prepares us for the next.
Baptism Blessings
PS—You can find all of the Book of Mormon videos here.