How to do backstitch for beginners:
Bring the needle up through the first hole in the fabric, then put it down into the second hole and up through the third hole.
Bring the needle back into the second hole and up again on the other side of the stitch you’ve just made, leaving a stitch length space.
Come back again with the needle and bring it up again in front, leaving a stitch length space. Make sure your stitches are even. The finished stitches should be of even length.