In regards to any dog's diet, experts recommend using foods consisting of ingredients native to the breed's country of origin. Being that the Papillon has a lineage of rat and rodent control dogs working on farms in central France, they consisted on the kind of food that was raised and grown there (not to mention the rodents they caught). In the 16th century, the era wherein their lineage is roughly traced back to, the meats available would be poultry and mutton. Also on the menu would be root type vegetables such as radishes and potatoes, along with wheat and corn. Not recommended would be any kind food that includes a soy product, fish, horse meat, beef, or rice.
For energy, vitamin B will work wonders for any dog, especially a breed as active as the Papillon. Natural food sources of vitamins are usually recommended over supplemental sources, but an owner of a Papillon with special needs should check with their veterinarian to be sure, as a dog that is recovering from an illness or is suffering some unpleasant condition might need more of somber vitamin or another than normal meal portions can provide.
As is common with toy breeds, supplemental vitamin C is not recommended. Ascorbic acid, sodium ascorbate, ascorbal palmitate, and calcium ascorbate can all do serious damage to the kidney and liver.
As for exercise needs, the Papillon, being classified as toy, is found to be fairly undemanding, which is the norm for such a small breed and so it's not the least bit surprising that they're a preferred companion dog of the physically disabled and the elderly. Needing nothing more than a small apartment for day to day living and a romp in either the front yard, back yard, or nearby park. In fact, there are even paper trained Papillons who are perfectly content to remain indoors most days. Of course, if this describes your dog, the need for vitamin D will require that sufficient sunlight is let in. If there aren't any windows in your house that allow the sunlight to come in for much of the day, then a daily walk will have to be a necessity. Exposure to sunlight helps the skin to produce the vitamin which helps organ development and health.
With regards to training, the Papillon is not known to be especially prone to any special requirements or temperament problems. A Papillon owner needs only to be gentle and consistent in the training process. A Papillon won't respond well to barked commands like larger breed dogs might and dependable patterns of punishment and reward provide comfort and encourage trust in the dog. However, to be considered with every breed, is that, while Papillons and children get along just fine, children can't be given the major duties of training. A dog, being of about the same mental age as a five year old child, can't be expected to grow and learn to their full potential without an adult human trainer to guide them into their adult life.