First time I saw the little dark square for no stitch I was totally confused, too.
But really it's very easy: No stitch = you do nothing.
Whenever there's that dark square, ignore it.
So the first row really only has 7 stitches. However, after that you increase every row so that the number of "no stitches" goes down each row. They just had to leave the extra dark squares in there to make the whole thing fit into a chart.
Just do it exactly what the pattern tells you. You'll be able to do this!
One extra word of advice: count your stitches after each row to make sure you didn't forget to do an increase, and mark your current row (sticky notes work good) so that you don't get lost in the pattern. It'll get easier with practice, really!