"For every two levels of extra experience, the wizard gains an additional missle - he has two at 3rd level, three and 5th level, four at 7th level, etc., up to a total of five missles at 9th level."

Don't all the characters you get or create start at like the 7th level? Does this mean you get four magic missles the very first time you fire the magic missle spell?

That's right.