I agree with what others have said about the church building, and church there. When I've been to church there, there were a couple international branches, and the locals also had a branch (e.g., nationals who were baptized at BYU and went back to China), but they weren't allowed to interact at all. We all met in the upper floor of an office building. In more rural places across China they have had a virtual branch, where people gather over zoom, kind of like the covid days.
My father in law still lives in China, but not in Beijing anymore after living there for many years. He's a cougarboard lurker, so maybe he'll reach out. There are a lot of others (like the Perkins family mentioned above) who I've gotten to know over the years, and all have seemed to have great experiences living in China. I think you should have a fantastic experience!