Countable nouns = nouns that we can count, for example: apples, bananas, chairs, houses - everything that has a plural "s" is a countable noun.
Uncountable nouns = are things that we can't count, for example: water, cheese, bread, time, money.
With countable nouns use a/an, some for positive sentences - use a/an any for questions and negatives
For example: There's an apple in the fruit bowl.
There are some apples in the fruit bowl.
Are there any apples in the fruit bowl?
No, there aren't any apples.
With uncountable nouns use some in positive sentences.
Use any for questions and negatives
For example: I would like some bread please.
Have you got any bread?
No, I haven't got any bread today.
How many is used to ask about quantities of countable nouns,
How much is used to ask about quantities of uncoutable nouns.
For example:
How many video games have you got?
Not many.
How much bread is in the fridge?
Not much.
I hope this helps!