Student or Learner
Is This Sentence Correct?
I don't know the name of the people whom you visited them?
The "whom" is right, but you need to delete the "them."
You can also omit the "whom."
I don't know the name of the people you visited.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.