Quantifiers are used to describe how much or how many of something we are talking about.
Some quantifiers are only used for countable nouns:
many - I have many friends. (many means a large quantity)
a few - I have a few friends. (a few means a small quantity)
Note: there is a difference between a few and few.
I have a few friends. - means I have some friends, but the number is not large.
I have few friends. - means I have nearly no friends.
Some are only used for uncountable nouns:
much - there isn't much milk in the fridge. (much means a large quantity, and is not used in positive sentences. lots of and a lot of are used instead.)
little - There is a little milk in the fridge.
Note: there is a difference between a little and little.
I have a little money - means I have some money, but the amount is not large.
I have little money - means I have nearly no money.
Some are used for both kinds of nouns:
a lot of - a lot of friends and a lot of money.
lots of - lots of friends and lots of money.
some - I have some friends and I have some money.
any - I don't have any money and I don't have any friends.
Some and any mean the same thing, but some is usually used for positive sentences, and any is used for negative sentences and questions:
I have some time, but I don't have any money.
Do you have any milk?