Translation:Who are you looking for?
Yes, that's grammatically correct but "Who are you looking for?" is normal spoken English.
i also think so, but i am not a native. could anybody native tell me which one sounds more natural?
"Who are you looking for" definitely sounds more natural if you're asking what someone is doing at the current moment. "Who do you look for" sounds like you're asking the person who he looks for habitually, as if he works as a hiring manager trying to find suitable people for a job.
A correct translation, but "dost" and "thou" are archaic. They went out of general use over 100 years ago. The word order is also old fashioned.
What would the sentence in Chinese be if it were saying "who is looking for you?"
I got the previous one wrong for not putting in 在 (我在找什么?). What's the difference between 谁 and 什么 that requires 在 for one and not the other, when both are so similar? ("Who", vs "what" are you looking for?)