There were many who knew Joseph Smith personally, sacrificed their prosperity and comfort to follow his teachings, and wrote about it.

• Joseph Smith saw God the Father, and His Son Jesus Christ, in 1820, in answer to an inquiry. He became the first modern prophet and president of the Church.
• I have read the journal/bios of several who personally knew Joseph Smith (first modern prophet and president of the Church), and the writings of such others.
• These people traversed the desert in wagons, built cities and schools, and were sent as missionaries to many countries, during their poverty.
• They were often educated and prosperous before deciding to leave their former lives behind and build the kingdom of God, with all their resources.
• They had reasons for it: they had read the Book of Mormon, seen the fruits (results) of the gospel for themselves, and believed it. Some were my ancestors.
• Article: The Miraculous Mission of the Prophet Joseph Smith
• A relevant Conference talk: "Joseph Smith"
• "Saints": Church history book series, volume 1 (narrative style for easy reading, while highly documented/referenced)
• Much more content on Church history (all free as far as I know)
• There is a very great amount of original source material about Joseph Smith available and increasing, at https://www.josephsmithpapers.org/ .
• Daniel Peterson, Arabist, has written much on evidences, & "apologetics" (or answering questions of critics) and about Joseph Smith, and refers to many others.