Exodus 18, Jethro’s advice.
Jethro was descendant of Keturah, which Abraham married after Sarah’s death. She bore him Midian, and Jethro was a descendant of Midian. Midian extended mostly east of the Gulf of Aqaba, but also included the southeast Sinai peninsula.
God appoints His spiritual servants, the people, not the apostles choose their civil servants. This is God’s will.
Moses early life is mentioned at length in two places in the New Testament; the Great Faith chapter: Hebrews 11, and in Acts 7, Stephen’s defense before he was martyred.