Keep yarn slack from developing in my work as I perform a basic knit stitch
From the image you've shown it looks like you're on the first row of knitting after casting on, and it also looks like you've used a loop (a.k.a. backwards loop) cast-on method.

It's common to get an ever-increasing amount of slack on the first row when using this kind of cast-on. A loop cast-on is easy to do, but hard to do well because the tension used when casting on is fiddly. If you keep knitting this piece the knit stitches will even out, but they might not even out completely.

I recommend starting with a long tail cast-on. It will take a little longer to get the hang of, but you won't have the slack problem.