conversationally, both are correct and understandable.

"could help find" is correct.

The verbs work but the sentences are not complete. You've got a noun clause but no main verb or object. Take out "that" and you'll have sentences that can stand on their own.

These are fragments, or possibly titles. They aren't sentences. The correct construction after 'find' is the infinitive, either with or without 'to', so the better option is 'could help find'. Using 'finding' could possibly be a shortened form of 'could help (us in the process of) finding', but it is grammatically doubtful and should be avoided. Go with your second option.

I couldn't help thinking if you find it helps finding out for yourself.