"Please help me a little bit."
I'm not a native speaker, but my understanding is as follows:
一下 is a little bit of time.
ex. wait a while: 等一下
ex. a quick look: 看一下
一点 (儿) is a little bit of something other than time.
ex. a bit of water: 一点水 (before nouns)
ex. a little cheap: 便宜一点 (after adjectives)
((Side note: 一些 (Yīxiē) also means "some" (ex. some water: 一些水) but is only used with nouns.))
When teamed up with 有(Yǒu) 一点 can also be used to express "a little too..."; 有一点 (儿) shortens to 有点 (儿) and comes before the adjective.
ex. 有点贵 = a little too expensive
I hope this helps, but I recommend AllSetLearning for more info on 一点 and 有点.