Newbie needs help

Hi there. My first ever project, started two days ago, was supposed to be a scarf but because I noticed a funny shape I bound (binded?) off early just to get a look at it. Sure enough, instead of a square I had a sort of trapezoid. The bind off row was straight(ish) but the sides went sharply inward on the way down so that the bottom row is much smaller that the top.

I used a “Chunky Alpaca” yarn, did a garter stitch, used 10 1/2 needles, and no pattern. I assumed I would get a square or at least a rectangle! Is it that I didn’t slip off the first stitch of each row but knitted it instead?

Please help me get from this :doh: to this :XX: !!!

Welcome!
I am not the knitting expert here - but as a newbie I know the mistakes I have made!

One of the most common mistakes with fuzzy yarn is insterting the needle just beneath the stitch. This causes an intentional increase.
Do this just a few times over the length of your project and one end does get wider.

But there is also the possibility that your tension on the yarn got more relaxed the more you worked with your yarn. So where your tension was tight the yarn draws in more.

Enjoy your scarf!
Your knitting will only get better. And no matter what your scarf will still keep your neck warm. And almost no one will ever notice that it is not quite the rectangle you envisioned!

All kind of odd things can happen when you first start out. You could have added stitches inadvertently, or as Quirky said, you just could have relaxed as you got more comfortable knitting. Save what you did and look at it in a few months. You’ll be amazed at your progress.