For me, I didn’t fasten the neck area too tight so that able to see baby’s wellbeing under the nursing cover.. As for the sides, can pull more on the side baby is latching. If you are not comfortable to latch baby in the public, you can always go to the nursing room to latch your baby. Most of the malls have nursing rooms.
U can try practising it at home until you are comfortable before using outside. Initially will feel a bit uncomfortable but after a while will be okay. The neck part should be loose so that you can see the baby and you should pull the cover more to the side that you are feeding so you won't expose yourself easily... :)