A few, a little, few, little

A few / a little means ‘some’ and so refers to a positive idea.
e.g. I have a few ideas that I’d like you to listen to. (plural noun)
We have a little money saved for our holiday. (uncountable noun)

Few / little means ‘not many’ and ‘not much’ and so refers to a negative idea.
e.g. They have few friends in this city. (plural noun)
There is little water. Can you fetch some more? (uncountable noun)