一下 in a moment 一点 a bit，一些 some

一下 be used when you describe an action or a movement such as one punch or one bite 一点 be used when you describe an small amount but less than 一些 一些 is made by some 一点s

一点点немного.（ваш китайский уровне) 一下一下下 час/подожди.(времени) 一些некоторый(что/чего)

一下：Less frequent or shorter time ——你看一下 一点：a little—— 我会一点汉语 一些：some —— 我有一些事

first of all you should say 我会说一点中文，一点goes before noun. not as strict as english, but 一点 is like a little for uncountable, 一些 is like a few for coutable。 一下 is only for time such as 等我一下，一下can be used to describe an action that takes a small amount time such as 数一下。