Question

Who gives you advices about worries?
- My friend, parents, and teachers give me advices about worries.

(Are the question and answer grammatical? Please focus on the form of 'advice' and the 'friend'?)

Answer 1

You need to use the singular form of "advice."

If only one friend gives you advice, then you're correct. However, most people depend on more than one friend -- friends -- for advice.