Train may mean the education or instruction of a child, an accompanying force or army, or the loose-hanging part of a garment. Its meaning depends on context: it may describe instruction, a military retinue, or the skirts of a robe.
In Proverbs, the verb refers to educating a child. The Queen of Sheba’s train means the force or army accompanying her. In Isaiah’s vision, the train is the loose-hanging garment, or skirts, of God’s robe.
The biblical terms translated “train” are not the same in every passage. The word connected with the Queen of Sheba’s train is the usual term for force or army, while Isaiah’s term denotes a loose-hanging garment.