Hi, Diego, you can say something like this:
Example 1: "While I am barbecuing, I see my brother going out to a dance on Friday. Just to be nice to him (I don't like him very much), I tell him: 'You can have a few ribs.'" If you're speaking in the past tense, I would say something like: "While I was barbecuing, I saw my brother going out to a dance on Friday ..."
Example 2: I would say: "Samsung is launching some new phones." You could also say "Samsung is launching a few new phones," but the other one sounds better.
We tend to use "few" when we refer to countable nouns like "a few pieces of candy," "a few students in the classroom," etc. On the other hand, we tend to use "some" when describing uncountable nouns like "may I have some water?" But sometimes, these words can be used interchangeably. It often depends on the context and how it's normally spoken in daily conversations.
