Sewing a straight line

I have been dreaming about sewing my own clothes for a long, long, long time. I have owned a sewing machine for four (and a half) years and I haven't sewn a single garment yet. More to the point, I still have approximately zero sewing skills. What has held me back?

I think the biggest barrier has been deciding where to begin. I'm not a good decider, or rather I am not a fast one. My creative process is painfully slow because of this, and my wardrobe building process is even slower... which creates a perfect storm of procrastination! So for my first "official" sewing project I decided-- after lengthy internal debate-- to separate the "acquisition of sewing skills" part of this endeavor from the "making garments" part. I just want to sew some straight lines!

With that in mind, it doesn't much matter what these cloth things are supposed to be, but let's just call them kitchen towels:

I thought this little straight stitching project-- hemming rectangles!-- would be something to breeze through on my way to bigger and better things. The point was to prove that I could get a project to the finish line and have a little victory dance, not to encounter any actual challenge. My sewing machine had other ideas.

I should back up and let it be known that I have sewn with my machine before in a very casual way and that I know how to, for example, wind the bobbin, thread the machine, change the stitch length & tension, etc. A remarkable store of knowledge, really, for having done not much with the thing in four and a half years, but still not enough to sew a straight line with it-- at least not enough to sew a straight line where I wanted to sew a straight line. Try as I might to keep the stitches close to the fold of the hem, the feed dogs kept dragging the fabric to the left, so that my stitch lines landed in the middle of the hem. Not pretty:

I described this problem to every sewing friend I have, including Google. No one could tell me what I was doing wrong, probably because I was doing something so fantastically incompetent that no reasonable person would think to tell me not to do it. I ultimately found out through a rather lengthy process of trial and error-- combined with watching this super helpful YouTube video-- in which I learned a number of things about my machine:

1. I was missing a step in the threading process-- not relevant to this problem but good to know nonetheless! 
2. The needle position selector moves the needle from the center to the far left or far right. I knew that already. What I didn't know is that the stitch width selector also moves the needle-- to any position I want! Neat!
3. When the needle position is set by the stitch width selector, the needle position selector can't move the needle back to the center position-- which to the uniformed makes it appear that the machine is broken! 
4. The correct stitch width for a straight stitch is zero-- not four. Guess where mine was set. 
5. Returning the needle back to the center position by setting the stitch width to zero magically restores the feed dogs to their proper functioning! They stop dragging the fabric leftwards! Being still at least partially incompetent I'm not entirely sure why this is, but I'm not going to argue with success:

On top: before-- on bottom: after. Much better!

Once I learned how to properly set up my machine for straight stitching, I won't say it was entirely smooth sailing. My stitch lines are still wobbly in places but I am learning to steady the fabric as it feeds-- working with the feed dogs rather than playing tug of war with them and losing. I began to enjoy the process of stitching slowly while gently guiding the fabric and was kind of sad when I ran out of rectangles to hem. I think that's a promising sign!

After all the difficulties I worked through in the process of making these cloth things I think I am more attached to them than I would have been had I breezed through the project as expected. Also they have pigs:

Maybe I need a matching apron? That's sort of a garment, right?