Internship

I have X1 visa. Im a bachelor student in Beijing. The company that I applied for Internship said that I dont need anything to work as an Intern for them. I have temporary residence permission. According to my researches on internet they say I have to take an admission ( I dont know what kind of admission) form my university and apply to Public Security Bureau. Please make me clear Im so confused about these processes. I dont know how to do. Thank you