First person lets readers experience events through the author’s memories and present understanding. It also requires care: the narrator can describe what they knew at the time, what they learned later and what remains uncertain. This distinction builds trust and keeps hindsight from being presented as real-time knowledge.
Read a scene aloud in each perspective you are considering. Notice how the distance changes, whether the emotional detail feels natural and how much explanation readers need. Once selected, maintain that viewpoint consistently through the manuscript and flag intentional shifts for your editor.