As someone who lived in Shenzhen for a bit I can kinda give you my opinions. You'll always feel like an outsider, but people are extremely friendly towards you.

As someone who lived in Shenzhen for a bit I can kinda give you my opinions. You'll always feel like an outsider, but people are extremely friendly towards you. If you make the effort to learn some Mandarin, people will greatly appreciate that. For me, as an introvert, I felt quite uncomfortable sometimes, people will randomly walk up to you and start a conversation, or they'll try to sneak a picture of you. And then you have the usual people who just stare you down. But I assume that's more because they don't see many Western faces. (Although Shenzhen has quite a large expat population) But I never had anyone being racist to me.