It should be a round loop of knitting. You won't have to turn to do the back.
To join you cast on and make sure the working yarn is coming from the right needle when you do first stitch. You can tell when you do the first stitch that they are joined.
Be very careful when joining that your stitches aren't twisted. Lay the cast on flat with the working yarn on the the needle to the right and align all the stitches. Now pick it up and knit the first row joining the stitches. If you mess up start over. We all do it occasionally.
If you find it hard to join w/o twisting you can knit a few rows of stockinette flat first, ending with a knit row, then join. You can sew a small seam when you're done.