That is actually a really good question. China has a role in global capitalism that is arguably the most important besides the USA/W.European core. With their Belt and Road project they are trying to turn themselves into a new core of trade and consumption and cut out the US in the process. I'm not sure what the plan is at the highest levels of the CPC, but I doubt they want to fall into conflict with the US for the foreseeable future while they are still building that.

Really all "support China" means to us is not to start howling for blood over some imperialist bullshit the US is trying to push right now. The US is definitely uncomfortable with China's position right now, and are trying to confront them in order to check their growing influence. Don't contribute to the propaganda drive that calls for regime change or anything like that. Besides that, there isn't much else for us to do. China runs its own affairs and our role in America is not to support interference.