This is the book that I found at the garage sale.
That clause modifies book. It tells is what book it is. Because "that" is not the subject of the clause, it can be omitted.
This is the book I found at the garage sale.
Even with out "that" it is a restrictive relative clause.
This book, which was written by John Henry, is the best reference for
This clause modifies "book" but is not necessary for the sentence to have meaning. In this case "which" functions as the subject of the clause.
More here: Clauses - Restrictive and Nonrestrictive
Unfortunately, there are differences of opinion about phrasal verbs. These are combinations of a verb and a preposition or an adverb. IMO, "phrasal verb" only applies to combinations that have an idiomatic meaning, that is, the meaning of the unit is different from what one would understand from the individual words. Unfortunately, there are those who see almost every sequence of Verb + prepostion/adverb as a phrasal verb. This causes a lot of confusion. There are also those who say that "phrasal verb" applies only to verb + adverb. When a prepsotion is involved, they call it a prepositional verb. I don't find the distinction to be very useful.
Because phrasal verbs are idioms, their meanings must be memorized as if they were vocabulary words. There are many phrasal verbs here:
I hope this helps.