Niether of those is a fallacy.
Oh dear. A fallacy is broken logic. There is no logic in "go buy a book and learn something". That is implying that the person arguing does not have sufficient knowledge. It is leaving the argument unspecific. It's merely a veiled attack on the person's intelligence as if they have never read a science book. So yes, it is a fallacy.
Many people familiarize themselves with only a few logical fallacies, and do not know that there are many many others. Here are some:
Genetic Fallacy
~The attempt to invalidate a position or belief, merely by showing how the position or belief originated.
Example :"Christianity arose because people feared reality, because people were scared of death. Therefore Christianity is false."
Ad Hominem Fallacy
~An argument that attempts to counter another's claims or conclusions by attacking the person, rather than addressing the argument itself.
Example :"You're an Idiot, only gullible, ignorant fools believe in God."
Argument from Personal Incredulity
~An argument thats attempts to disprove or negate a position because the individual either does not understand and/or explain and/or imagine it.
Example : "God seems so illogical to me, he can't possibly exist."
Appeal to Ridicule
~A fallacy where ridicule or mockery is substituted for evidence in an argument.
Example :"You can claim that God exists all you want, the theistic position is still laughable and illogical."
The Masked Man Fallacy (Illicit Substitution of Identities)
~A fallacy where an assumption is made that because something is known under one perspective, that it must also be known under a different perspective.
Example :"Thousands of years ago people believed lightning, rain and droughts were caused by a/the God(s). This has been disproved by science. Others believe in fairies and this is untrue. Therefore God played no role in the creation of the Universe."
Appeal to Pity
~The receiver is urged to accept arguments based off an appeal to emotions or sympathy."
Example :"How could you honestly believe in God when there are starving children in Africa?"
Guilt by Association
~Rejecting someone's argument because of the person's friends, religion, topic standing etc.
Example :"Why should I believe anything you say? You're a Christian after all! Religion has been responsible for horrible atrocities"