Can we rely on Buddha's quotes found on internet? I found many quotes on internet but if we'd think we do not find any reference in any scripture so do we need to ignore them as they are possibly fake quotes?

I found such:


  "Three things cannot be long hidden: the sun, the moon, and the truth."


I can see search generate result by this site 'fakebuddhaquotes.com'  


  “Better than a thousand hollow words, is one word that brings peace.”


So are we supposed to ignore if they are fake and if not, what is second quote's meaning?
On the same site -- http://fakebuddhaquotes.com/better-than-a-thousand-hollow-words-is-one-word-that-brings-peace/ -- the author identifies the second quote as a slightly inaccurate or poetic translation of the 100th verse of the Dhammapada:


  Sahassamapi ce vaca
  anatthapadasamhita
  ekam atthapadam seyyo
  yam sutva upasammati.
  
  
  Better than a thousand words that are senseless and unconnected with the realization of Nibbana, is a single word of sense, if on hearing it one is calmed.
  


That too is not a literal translation into English -- http://www.tipitaka.net/tipitaka/dhp/index.php says they refer to the commentary if the literal meaning is vague or unintelligible or perplexing -- they added to the translation the phrase "unconnected with the realization of Nibbana" to clarify the difference between what they called senseless and sensible, i.e. between anattha­pada­saṃhitā and atthapadam.

Here is maybe a more literal translation:


  
  Better than a thousand useless words is one useful word, hearing which one attains peace.
  


Note that's close to the version you quoted in the OP (it's so close that I don't see why what you quoted is listed as a "fake" quote, instead of being listed among the "real" quotes).

If you still don't understand it, I recommend the commentary/story which accompanies each verse (see here), and/or reading the whole chapter of the Dhammapada (see here).