Metaphor is a figure of speech used to somehow compare to seemingly unrelated things through a feature they have in common. Basically, that means we express one unknown thing by comparing it to another known thing.
Onomatopoeia is, basically, creating a word from a sound it makes (buzz, splash, slam, bang etc.)
Paradox can be defined as a statement that, when logically examined, contradicts itself.
Personification is, simply, giving living beings' features and traits to inanimate objects.
Blueprint is design plan or a sketch or an idea for something. Of course, there is no such thing for achieving one's happiness. But knowing that main feature of a blueprint is an idea, a plan, we know that the author tried to say that Alexander's plans differed from his family's, meaning that blueprint is a metaphor for plan or idea.