Meaning

[Q] 1.here why "comma" before "and" has been used.

(1) He decided to go to USA, and to lean English there.
(2) He decided to go to USA and to lean English there.
(3) He decided to go to USA and learn English there.
They all mean the same. You'd better choose sentences of type #3 when two infinitival phrases are short like this example. But when each of them are long as the case of your example, a sentence of type #1 would be easy to speak and easy to take the meaning. If you don't put the comma, the sentence should be paraphrased like this;
He decided to drink the water of one coconut then and there and carry home half a dozen more.
Is it easy to take the meaning?


[Q] 2."half a dozen more". what is meaning of this?

half a dozen = 12 divided by two = 6. "Half a dozen more" means "six coconuts beside that one"

paco