You can take any talent from the class-specified list at first level, regardless of requirements.
The book pretty clearly states the general-case answer in the Talents section on page 35:
Each talent lists the classes it is available to; you cannot take talents that are not open to your class. Most talents also have requirements, like specific focuses or weapon groups. If you don't have the requirements, you cannot take the talent.
However, there's an explicit special case for starting talents. First; those talent rules state that they apply to spending the talent points you get when you "gain an odd level (3,5, etc.)", leaving first level out of the list. Second; the first level part of the class advancement chart doesn't say you get a talent point - it straight up says
you become a novice in one of the following talents:
i.e. without spending a point or having to meet requirements. That doesn't mean you shouldn't come up with a decent backstory excuse for your character though - there must be some kind of extraordinary reason that they can do what they do lacking the usual prerequisites.