Student or Learner
I wonder if there is a little difference between "1" and "2"
1. What should I do?
2. What do I do?
If no, which is more used in a situation?
In general, number 2 is more emphatic - a stronger cry for help.
But you are right, they are very similiar and can differ in the strength of the request depending on the context and especially, like in most cases of expression in English, by the strength of the tone/pitch.
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