Which edge are you referring to? Is it the cast-on edge or one of the side edges?
If it’s the cast on edge, you may have started out knitting more tightly or it may be that your tension when casting on was uneven. This is really easy to do when you first start knitting and it takes some practice to get it even.
If it’s one of the sides, after you finish the row and turn your work, when you insert your needle into the first stitch in the next row, give your working yarn a gentle tug. This should even up the stitches on the edges. Usually both edges on a piece of knitting tend to look a bit sloppy, but :shrug: