This study explores how middle schoolers interact with and conceptualize generative AI tools, specifically ChatGPT, through a focus group study at a science museum. The research aims to identify personally and culturally relevant topics, characterize their approaches to interacting with ChatGPT, and understand their conceptions and misconceptions about AI capabilities. The study involved 24 middle school participants who freely explored ChatGPT, guided by their own interests. The findings reveal three distinct interaction approaches: AI testing-oriented, AI socializing-oriented, and content exploring-oriented. Participants discussed a wide range of topics, including school subjects, hobbies, pop culture, and current events. The study also identified common conceptions and misconceptions about AI, such as assigning human attributes, comparing AI to other tools, and assumptions about AI's intelligence and capabilities. The results provide insights for designing effective AI literacy interventions, particularly in informal learning environments like museums, to foster broader and more inclusive AI literacy among young people.This study explores how middle schoolers interact with and conceptualize generative AI tools, specifically ChatGPT, through a focus group study at a science museum. The research aims to identify personally and culturally relevant topics, characterize their approaches to interacting with ChatGPT, and understand their conceptions and misconceptions about AI capabilities. The study involved 24 middle school participants who freely explored ChatGPT, guided by their own interests. The findings reveal three distinct interaction approaches: AI testing-oriented, AI socializing-oriented, and content exploring-oriented. Participants discussed a wide range of topics, including school subjects, hobbies, pop culture, and current events. The study also identified common conceptions and misconceptions about AI, such as assigning human attributes, comparing AI to other tools, and assumptions about AI's intelligence and capabilities. The results provide insights for designing effective AI literacy interventions, particularly in informal learning environments like museums, to foster broader and more inclusive AI literacy among young people.