In this context, naive means to be inexperienced and innocent in terms of age. It can also mean to be foolish- without judgment or wisdom in a situation.
Ex: Jane acted naively when they asked her questions. She pretended to know nothing.
Ex: I was so naive when I said yes to that scammer! They took all my money. => lack of judgment or wisdom.
Ex: Peter was so naive in his twenties. He's matured a lot now.