1. Explain it simply
真 (zhēn) means 'really' or 'so'. It adds emphasis: 真好 = really good.
非常 (fēicháng) means 'very' or 'extremely'. It is stronger than 很: 非常好吃 = extremely tasty.
有点儿 (yǒudiǎnr) means 'a little' but usually with a negative feeling: 有点儿贵 = a bit expensive.
好 (hǎo) can combine with verbs to form adjectives: 好吃 (tasty), 好看 (good-looking), 好听 (nice to hear), 好玩儿 (fun).
2. Show examples
这个电影真好看。
Zhège diànyǐng zhēn hǎokàn.
This movie is really great.
真 + adjective for emphasis
饺子非常好吃。
Jiǎozi fēicháng hǎochī.
Dumplings are extremely tasty.
非常 + adjective for strong degree
这个衣服有点儿贵。
Zhège yīfu yǒudiǎnr guì.
This clothing is a bit expensive.
有点儿 + negative adjective
这个歌非常好听。
Zhège gē fēicháng hǎotīng.
This song sounds really nice.
好听 = pleasant to hear
3. Share a tip
有点儿 is usually used with adjectives that have a negative meaning (贵, 忙, 冷, 热). For positive feelings, use 真 or 非常 instead.