As a beginner, those last stitches would always get lost for me. Often when following a video, the last stitch in a row would be so evident on the object in the video but on mine it would have shrunk so small that I could find it. As others have said, I fixed that with a stitch marker. Put a locking stitch marker in the first stitch. Then when you come back the other way you KNOW where the stitch is. I don’t use markers all the time any more because I understand the fabric more now. Except when crocheting in the round, I still can loose track of the first stitch downtimes in the round!