CPUs don't have a interface. FYI Chinese boxed CPU just have the words outside printed Chinese. Inside is the same as anywhere else.
Motherboard BIOS have interface. Maybe Chinese set will default to Chinese. But if your Chinese is good enough to buy on Taobao then it is good enough to change the settings to English.
Don't have some silly thinking that everything from China means is fake or bad. Read the shop reviews, check how long the shop has been around, talk to the shop owner ask them is it 全新未拆封 or 拆机, most of them are very responsive. All this info is available on Taobao. Chinese themselves also know how to choose legit goods and not get cheated. Same for Shopee, you can always read reviews and shop info. Don't have some old uncle thinking suspicious of everything and use the tools you have now to help you make a wise decision.
Disclosure: I myself bought 3 ryzen 5000 CPUs from different shops on Taobao and never had an issue with it. Later on I sold them cos switch to Intel and my buyers also never had an issue with it. I never buy mobo on Taobao before, because I found that for mobo, actually Taobao tend to be more expensive for the higher end mobos, esp standalone. For low to mid end, I think is fine, but if is same price, I prefer Amazon or local retailers via Shopee (many of the SLS shops also sell on Shopee). Have also bought 2 different CPU cases/chassis from Aigo, Jonsbo, AIO from Jonsbo, AsRock Deskmini chassis with custom powerblock etc all no problem. The shop I bought Jonsbo from, the owner even alerted me that I chose some incompatible components and let me cancel and re-order the correct items, not once but two times. Way more respectable than what I can say for some unscrupulous local SLS retailers.
P.s. for power supply it is one thing I will suggest get local better. Simple reason is most PSU you are familiar with e.g. Corsair, Cooler Master, are not much cheaper on Taobao and can even be more expensive. But if you want to get from Taobao, just ask them whether it support 240V AC input. Additionally you will need to get ready a UK 3-pin cable or adapter as it ships with the standard China 3-pin plug.