>>10187001>Eh, I don't know shit about plumbingthis isn't 'knowing shit about plumbing' this is being a functional adult. If you live in anything remotely modern there should be a squiggly 'S' shaped piece of piping under the sink. This is a P trap. Water sits at the bottom curve preventing sewer gases entering the house, and as a happy side effect, it collects small dense objects like airbrush nozzles. The trap should be flanked by two unions, so unscrew the large nuts on either end and remove the entire trap assembly. Dump into a safe location and find missing nozzle. Screw trap back into place. Run water briefly to fill up trap. Done.
If you still feel lost consult youtube. If you really take your time, between youtube and actually retrieving your nozzle, it should take about 30 minutes. Do you make 40 pounds per hour?