Properly cleaning the toenails is important, because they contact with germs and bacteria. When washing both feet, use warm water and mild soap.
If your toenails have fungal, you can try topical whitening or anti-fungal agents. These treatments are usually helpful. If your toenails have severe discoloration, you can use laser to whiten the nails, similar to whitening teeth. Oral anti-fungals can also be an option.
As for heel skin peeling, you can try exfoliating creams. Straightly trim the toenails, otherwise you will have ingrown toenails.