When does one use only "tìm" instead of "tìm thấy"? They both seem to mean "find".
Tìm means to search, not to find. Tìm + thấy = search + see = find
What's the difference between "giúp" and "giúp đỡ"? They both translate as "help"?
From the hints in DL, there is not much difference in meaning. It seems that giúp is common in conversation, and giúp đỡ is more common in writing, or perhaps in more formal speech.
Can we use kiếm in place of tìm?
Yes, you can. Tìm = kiếm
Why "do"? I thought "con" took care of "that".