What's the difference of these two and are they used only for the place you originated from?
I (am) from -> 我從____
I am from Canada -> 我從加拿大來的
Note: "來的" has to be added at the end to show "從加拿大" is to describe where you came from, or else "我從加拿大" is an incomplete sentence in Mandarin.
I come from -> 我來自____
I came from Canada -> 我來自加拿大
I won't get into too much details on the usage of "從", as that seems to be a different topic from what you're asking.
As for the difference between the two, I can't think of any right now. Just like they both mean the same thing in English.