# 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]])