Different machines feed fabric differently. On some, a walking foot is almost essential. On others, they do OK without it. One way to figure out if you need a walking foot is to do a long seam where you start out with the two fabrics absolutely the same length. Then stitch, don't pin, If at the end you have an uneven end that is significant, a walking foot would probably make a big difference with feeding the fabric. Of course, changing pressure might help a bit and also pinning will help a bit. Just will be a lot less fussing with a walking foot as both pieces will feed more uniformly. If you tell us which machine you have, folks may be able to tell you what their experience has been with that particular machine.