Leave him to settle, if you are using plastic plants, just check there are no sharpish edges on any of them and give them a good clean every 3rd water change.
Don't put in any more salt for now, let it dissolve away with your water changes.
He has come from the shop, has new water parameters, new environment, maybe even different food.
If he is swimming well, alert, and eating healthily leave him alone, maybe put some light aeration in the tank.
It can take a few weeks for his body to acclimatise to his new home
Hope this helps
Mandy, Marine biologist/Vet