Eyelets are super easy!!! They can add cute details in children's clothing because your can run ribbon through them. Or leave them as is. And of course they are used in lace knitting.
Try doing a sample swatch so you can see how they work. Eyelets are worked by perfoming a YO or YF (yarn over, yarn forward, and then often followed by a decrease so that your stitch count stays the same.
Try this, cast on 20 stitches, knit 2, then bring your yarn forward EXACTLY LKE you wanted to purl next (but you won't). With the yarn still forward knit the next two stitches together. You now formed a new loop (looks a little different than a regular loop) and decreased one stitch, so you have no net gain or loss of stitches. Then K2, yf, k2tog to the end of the row.
On the next row PURL all the stitches including those slightly odd yarn over stitches (they will feel very loose but that's what forms the hole to make the eyelet).
Knit the next row and you'll be able to clearly see your beauitful eyelets.
Hope that helps. I'd love to see a pic if you try it!