My doubt came with these 2 sentences (I don't know if it is correct):
Je ne sais pas comment parler pour moi-même.
J'ai étudié pour moi-même
Doing a little bit of research, I found the form par moi instead of pour moi. What's the difference between them and which one should I use in both cases?
(1st should be: I don't know how to talk (french) by myself; 2nd: I studied on my own)