If a noun is in singular, we use a little Example: a little bit, a little time,etc If a noun is in plural, we use a few Example: a few friends,a few minutes,etc

It depends on the noun. Use "few" for countable nouns (car, desk, friend) and use "little" for uncountable nouns (sad, hope, salt). "a few" and "a little" usually have positive/neutral nuance while "few" and "little" have negative nuance, usually we add "very" or "just" there. I have a few friends. (maybe my friends are only around 3-5 people, not many, but enough) I have (very) few friends. (my friends is not many and I'm sad about it) I have a little time. (I have some minutes, and it's okay to spend it) I just have little time. (I'm in hurry, I'm not willing to spend it much, so please be quick)