I don't find it. - not good English
I can't find it. - good Eng.
Explanation: I have no idea why but I pretty sure that I don't find it is not grammatically correct.
There is nothing grammatically wrong with, "I don't find it". It is just an uncommon phrase so it sounds odd.
Is there a rule of thumb to know better when to use אותו and when to use את זה?
What is the difference between עמוד and דף?
דף = Paper leaf
עמוד = Page, one side of a paper on which something is written
דף -- would be just find here, really
Would it be acceptable to omit "אותו" in a colloquial speech?