What was Montag searching for(in general)? What is Beatty’s role in the fulfillment of that search?

Montag is searching for meaning..... for knowledge. Beatty was once very like Montag..... and because of his own experience is able to provide Montag with the history, knowledge, and justification for the way things are. He is Montag's superior and antagonist, but he also serves as Montag's guide and mentor.