Well, I guess I have an explanation. To talk about an unspecified amount of something the partitive article is used, which is di + definite article. An unspecified amount of butter would be "del burro". However, the partitive article may be omitted. Therefore if we discuss "butter" in general it is "il burro" if we talk about an unspecified amount of butter it could be either "del burro" or just "burro".
"Non" basically makes a statement negative "Lei non mangia", "Lei non beve", "Lei non è una ragazza. ", take out "non" and then she will eat, drink and be a girl. "No" for what I know is used to answer a question for example.
"Tu bevi succo?" "No, non bevo succo." (or you could just say "no")
The sound of a single c or a double c (cc) depends on the letter that follows it. Both the single and double c have a hard k sound when they are followed by any letter other than e or i. When they are followed by e or i, both have the soft ch sound. The double c, just like any double letter extends the sound of the letter when pronouncing it. For example, nono (ninth) and nonno (grandfather) sound slightly different because one holds the double n (nn) a little longer than the single n.
That is why some plurals have an added h. The h keeps the hard k sound. For example, the plural of amica is amiche, not amice.