Do the simple things. Brush and floss your teeth daily, morning and night. Try to avoid food or drink with dark colors. You want whiter, brighter smile?! Call me. :-)
No, unfortunately once gum has receded it does not grow back.
But, there is procedure called gingival grafting/connective tissue grafting to restore gum line.
Consult your dentist or have your dentist refer you to periodontist, who could evaluate the periodontal condition for proper treatment.
What's the best way to keep healthy white teeth?