I'm not really able to say anything specific about where you're going, but the whole of the UK is very multi cultural so you'll meet lots of people from all over the world, and probably lots of Chinese students (because many universities in the UK have lots of Chinese students). Basically, people are people (wherever they come from) and so you'll meet some nice ones that might become friends and some who you won't like. Also I think many of the other students will be feeling just like you are: it's natural to be a bit nervous. But the vast majority of students have a great experience, and even a negative experience is something that we can learn from.
Personally I think Italki is good in many ways, but I think you should be a bit careful about using it to make friends that you might actually meet in the real world... it's not really designed for that. And I think there's a risk that some people might see a young woman traveling to another country as potentially someone they can exploit. I think you'd be much better off contacting your university and asking them if they have any forums where new students can meet each other...or maybe where you can talk to existing students to find out more about the area etc