I've heard the suitable learning method differs by child (visual or auditory preference, reward strategies, etc.). I don't know which suits mine.

A theme to handle carefully. In common: the idea of pinning a child to one type—"this child is visual or auditory" (so-called learning-styles theory)—has weak scientific support. More reliable is trying several methods suited to the content and adopting the way that works for the child. Many children understand better when you combine several—words plus pictures plus real objects. What the family decides: which methods to use, and how much, is chosen by watching the child's reactions. A guide: "when you actually try it, with which method did the child understand and succeed?" Rather than "hunting for a type," "try it and use what fits." The child's reaction is the best clue.