Any word yet on the fecal?!
Thats super cool you and your son are into that! However…there really is so much junk and debris in poop! I honestly wouldn't be surprised if what you were seeing was actually a fiber (hair, cellulose from a plant-very common misidentification in human samples). I know I am a kill joy right now. I swear my microbiology instructors got such a laugh out of all of us. Here we would be looking at poop and so hopeful to find worms and our faces would light up with our big discovery, and then the crushing blow, "Nope, not a worm. Its a fiber."
If it is indeed pin-worms then you wouldn't necessarily need the scope. Adults are 2-13mm in length depending on M/F, and eggs are rarely found in feces due to adults laying eggs in the perianal regions.
What scope are you getting?! I want one so bad so I can do my own blood labs at home and the occasional O&P's (vets charge outrageously for them). If you want to see anything I would suggest a 10, 40, 100x light microscope and make sure you get oil for your 100x. I use Nikon and Olympus, both are lovely

As for identification, we used the lab book "Photographic Atlas for the Microbiology Lab 4th Ed." (can probably get it on B&N cheap!).