点 (traditional 點) is 黑 (black) + 占 — a small black mark, a dot or speck. From 'a dot' it spread to many useful senses: a point, a bit, o'clock, and 'to dot/select'.
点 is one of the most multi-talented characters you'll meet. As TIME: Chinese tells the hour as 'how many dots' — 几点? (What time?), 三点 (3 o'clock). As QUANTITY: 一点 / 一点儿 = 'a little bit' (我会一点 = I know a little). As an ACTION: 点菜 = to order food ('dot the dishes' you want); 点头 = to nod ('dot the head'). One character, your whole day: the time, the amount, and ordering lunch.
A small black dot — a POINT, a bit, and 'o'clock'.
Chinese tells time in 'dots': 几点? = 'how many o'clock?', 三点 = 3:00. The same 点 means 'a little' (一点) and 'to order food' (点菜). A true multitasker.