Many vs. much
There are quantifiers that either quantify inherently plural nouns (e.g. people), or countable nouns in the plural (e.g. presents). The most important member of this group of quantifiers is many:
(1) There were many people at the show.
(2) She gave them many presents.
Note, by the way, that example (1) shows that the predicate verb (were) agrees with the postponed subject (many people).
There are also quantifiers that can only be used to quantify uncountable nouns (sometimes also referred to as "singular nouns"). The core member of this category is much:
(3) He gave them much advice.
The most important fact to remember when it comes to the use of quantifiers in English is this difference between much and many, that is, that much is used to quantify uncountable nouns and that many is used to quantify countable nouns.
You can also read more about countable and uncountable nouns and about inherently plural nouns if you follow these links.