Do you know what the first thing they will do?Technically correct, but I think you're being a little bit naive to equate the willingness of other nations to impose trade sanctions on Russia vs the same willingness to impose sanctions on China.
The ability to wage economic warfare is quite related to the degree of importance of the target nation both as an importer of one's own products vs being an exporter of goods -- in other words it is not merely about what China can export to other nations for their demands, but also what other nations wants to export to China for their own economic growth. In other words, by sanctioning China they're losing a major market for their own goods, and they'll have to weigh those losses in GDP.
That can effectively be summed up by the place in which various nation ranks China in terms of their "most important" trading partners, and depending on where one looks, about 124 nations or territories consider China to be their most important trading partner (from 2012), not to mention China having taken the mantle of the world's largest trading nation about two years ago in 2014.
I'm not sure how many nations counted Russia as their most important trade partner back in 2013 before the sanctions began in 2014, but I think it would be reasonable to assume that they would be far less.
So it may well be possible for various nations around the world to try and place economic sanctions on China, but you are kidding yourself if you think it would be anywhere near as painless as placing sanctions on Russia. It would require substantially more political resolve as well as carry significant more economic damage to the nations doing the sanctioning as well due to the loss of China as an export market and Chinese economic retaliation.
They will freeze overseas asset of high ranking CPC officials and business figures that are close to power. This includes family members as well and since many of the Tax havens are now closed it going to be very difficult to do any behind doors negotiations with it.
Next modern sanctions are selective so neither side suddenly collapses but many of advanced components and sub-components will be banned so maintaining a military becomes a problem. Just by stopping shipments of ball barrings is enough to sabotage various equipment since we all know that PRC ones are sub par with a High ranking official openly criticizing PRC's defective ones saying PRC can't even manufacture the same quality ball point pens as the Japanese and PRC requires to import them.
At the end it's going to be a big chicken race but the rest of the world has a big advantage.
Ohh, I almost forgot many of the rival companies competing with PRC rivals would love to see PRC being placed under sanction being able to fill in the void.