I'm not sure what stitch pattern you're using but with patterns like stockinette you can knit it forwards or backwards and it'll line up just fine. This tutorial
is for changing the length of a sweater but the idea is the same. The working yarn should be dangling off the tip of the needle in your left hand and you should be able to pick up the yarn and start knitting. You may be starting with the front or the back side, depending on which side is facing you and you'll have to pick up the pattern stitch accordingly.
Good luck with this, which should work well and congrats on finishing (almost) your first projects.