In modern English “confident’ is almost always an adjective. Having studied for a test you feel confident about passing it. You’re in a confident frame of mind. This spelling is often misused as a noun meaning “person you confide in,” especially in the misspelled phrase “close confident.”

The spelling “confidante” suggests that such a close friend might be a female, and conservatives prefer to confine its use to refer to women. But this spelling is also very common for males, and the spelling “confidant” is also used of both males and females. Either one will do in most contexts, but the person you trust with your deep secrets is not your “confident.”