Hey ,
Gum recession is mainly due to improper oral hygiene . This is happened over a period of time because the deposits were their so the bone recessed down and the gums follow the jaw bone and that's how you have recession . A through cleaning (scaling ) every 3-6 months is specially required in your case for preventing further recession .
Gum recession and orthodontic treatment would not be co related , so you can go ahead with the orthodontic treatment . Age isn't a barrier to get the braces done your alignment problem will be solved post orthodontic treatment.
Next Steps
Visit a nearby dentist
Health Tips
Post cleaning do salt water warm rinses so that you can soothes the gums which would be inflames because of the deposits .