Need help with litter box training

My nephew gave me his cat that he adopted from the humane society. He wanted to adopt another dog and it didn't work out with the cat. She will not use the litter box all the time and urinates on my carpeting. I have pheromone plug in to see if that helps. Can anyone give me any suggestions? She remains in our bedroom, have carpeting throughout the house cannot afford to replace all our carpeting. She had accidents at his house also. She is a very sweet kitty but doesn't like to be held . She will curl up in bed with me , and lick my hands. Not mean at all, so I do not think she is a feral cat at all.