有点儿 = 有一点儿
We commonly use them in this way:
1, sb/sth + 有点儿 + adj
in English, we say sb/sth is a little xxx. We could understand 有 as "be",，点儿 as “ a little"
eg: 他有点儿伤心 he is a little upset.
她有点儿不高兴 She is a little unhappy
这道菜有点儿辣 the dish is a little hot
2.there is/are some xxx 有=there's 点儿 some,,,
eg. 这里有点儿面包 there're some breads here.
1. a little (use it with 有）
2. sb/sth 一点儿 + 都 + negetive（不xxx), = not.. at all
这道菜一点儿都不好吃. the dish is not tasty at all.
他一点儿都不友好 He is not friendly at all.
3.n, some...prefer something mentioned before
--Would you like some vegetables?
--好的，来一点儿，ok, please give me some.