There are two clauses joined by a conjunction which makes this sentence a compound sentence. To clarify further, the sentence describes two separate subjects: going to the library and finishing homework. Joined by the conjunction, "and," the sentence is now compound. To be a simple sentence, it can only refer to one subject per sentence.
A lot of advice is available for people who want to form new habits for themselves.
Explanation:
Since the antecedent is plural, then the pronoun must be plural. People wishing to form new habits ought to be given a series of advice on how to go about it.
