What You Did
You found the instructions your cells use in your whole body; you found your deoxyribonucleic acid or DNA.
You isolated a couple strands of your own DNA, and if you have access to a microscope, you were able to observe it under magnification. You broke down the cell membranes of your cheek cells and used the properties of density to recover the DNA strands.
You may not have scraped your cheeks enough to release enough cells, or maybe just by chance you didn't pour any DNA into the spice jar and so you did not observe any strands at all.
Try extracting DNA from other living things, like your dog or a strawberry
cells and organelles, DNA