When something is lost, the owner looks for it. After that, he/she either finds it or fails to do so.
For example, Janet was looking for her cat, which went missing. After an hour, her mother might be anxious and ring her on her mobile phone, asking, "Have you found your cat?"
Janet may reply, "I'm still looking for it. I'm very sad."
One way that you can properly use "finding" is when you are in the process of doing something (so the present progressive is correct) and you discover something on a repeated basis.
I'm reviewing your report and I'm finding a lot of typographical errors.
I think the difference between the two sentences are seemingly clear so as a matter of fact we know that "find" is much more common in both spoken and written English than the expression "look for" so actually both of them are used in a very general way ... but i think that " find " used when you are searching about something else where at that moment you know where it could be put you can say yo