Adjective: my parents are very caring people.
You are so caring. [not usually used with friends like that]. It is a very strong phrase in fact. So, you might say your parents are caring people and would probably say: Oh Mum, you care about me so much. [or: You care about me so much] And not: Oh Mum, you are so caring. Unless you mean how your mother is in relation to others, like the poor etc. to be caring = to be generous and nice to others.
Verb: My mother cares a lot about me.
My cousin doesn't care a lot [or much] about me.
As has been pointed out, a lot is used in the declarative.
much and not much can be used in the negative and interrogative:
- Do you care a lot about him? Do you care much about him?
- They don't care much about us. They don't care a lot about us.
- Do they care about you? Answer: Not much, not a lot.
- I really care a lot about my dog.
Word of advice: to care about a person means to like or even to love. The more formal term is: to care for a person (like or love) but it also means: to take care of, as in: My mothers cares for my disabled aunt.
As an additional word of advice: much, many in most declarative sentences in spoken English becomes a lot of or lots of rather than much or many. In the negative and interrogative, many or much is used but a lot and lots of can also be used. (This is just a general idea here. Not every detail of usage. And I am not distinguishing here between adverbs and adjectives, for the record).