The oscilloscope maximum memory is 24 million samples, more than you'll ever need. In case yours is not unlocked to 24 millions sample and all the other features, there are topics here about how to unlock all the features, free and without any risk (it's a serial number you introduce to unlock features, and there are online or standalone code generators).
Having such large memory, you can chose the sample rate and seconds/division such that to catch many sparks in the selected time frame. Then, put the oscilloscope on stop, then zoom and scroll to inspect each spark.
Practice this this from the physical knobs and buttons at first, with the test signal internal to the oscilloscope (has a metal pin with signal on the right hand side, outside the case) then once you know how to handle the settings, you can switch to remote software if needed. It's easier to learn with the physical buttons, each software has it's own quirks, remote control tools might have their own limitation.
But first, read the oscilloscope user's guide.