I'm new ro synthesis too!
So, first of all, there are no samples. These sounds are made (synthesised) from rudimentary waveforms.
In this case, there's just one wave, of type sawtooth, from one oscillator (<carrier-blam>). I'm able to add more <carrier-blam> elements for overtones/harmonics but that's not needed here.
The curve prop is a more flexible way to define an envelope. Usually it's in 4 stages (ASDR). The second valie of each pair indeed the time, but it's in beats.