How to teach a puppy not to go on the floor,

Hi, I'd like some information about toilet training (specifically regarding Eli, the 3-year-old adult female): how to train her not to go on the floor or even use a litter tray if possible, plus advice on walks or letting her go in an authorised area (like the woods), her temperament with people and how easy she is to train (easy, average, or difficult).

Thanks all,