And welcome to the wonderful world of knitting! Sounds like you’re already having an adventure! Well done!
I’m not sure, but it sounds as though when you turned the work the last stitch on the row you just knitted slipped out.
Try turning the work back around to where you’ve got all the stitches on your right needle except for the last little guy on your left. Then knit (or purl, depending on your pattern) that last stitch and then turn your work. That should start you off with all your stitches on the left needle waiting to be worked.
If this doesn’t solve it, write back in and let us know. Meanwhile, have a wonderful time with your knitting!