Being uneducated means not having attended much school. Someone who's uneducated hasn't had a lot of formal teaching, but that doesn't mean they're not intelligent.
Plenty of formally uneducated people go on to do great things and live happy lives. But if you're really curious about a subject, or you want to become a doctor, teacher, plumber, or veterinarian, you'll need to get educated by going to school or otherwise being taught. The word uneducated comes from the verb educate, "provide schooling," and its root, which means "bring out" or "lead forth."