Nice knitting, dude! Your stitches look great. I think your hole might be an accidental knit 2 together decrease. If you've not already frogged, see if you can tell if you knitted 2 together when you pull that one out. I thoroughly dislike counting stitches but learned that it can be a lot faster and easier in the long run. In my earliest knitting I placed markers, you could use anything that will go on the needle between stitches and not snag your yarn--a small loop of contrasting yarn works well--and know you should have a certain number of stitches (pick a number, 1/2 or 1/4 your total stitch count) between markers and it helps figure out where your count is off.
Happiness is catching that dropped stitch while it's still fixable..