Is there free software I can use to make a semi professional video?

I'm trying to create a short 1-2 min.multiple scenes and photos. How can I accomplish this using just an iphone while making it look professional.

I don't know about iPhone
but do you mean "free" as in gratis
or "free" as in http://www.fsf.org/?

If you mean gratis, there's "Movie Maker" for Windows.