I've noticed that начало means beginning and сначала means first (in the sense of precendence in time), for instance:
At the beginning of June I bought the table first.
is translated as
В начале июня я сначала купил стол.
Beginning and first (with the above meaning) are indeed related concepts. But in English, for instance, they seem to share nothing (in the sense that for the above meaning, i.e. coming earlier in time, the same word as the numeral meaning of first is used).
Why are they so close in Russian?