en_tn/jhn/04/39.md

believed in him

To "believe in" someone means to "trust in" that person. Here this also means that they believed he was the Son of God.

He told me everything that I have done

This is an exaggeration. The woman was impressed by how much Jesus knew about her. Alternate translation: "He told me many things about my life" (See: rc://en/ta/man/jit/figs-hyperbole)