You can train a small dog to use a litter box or a urine pad. Both are pretty easy in my experience. I personally use a urine pad with my Pomeranian. I simply placed her on the pad and praised her when she urinated on the pad. It was pretty easy and certainly no harder than training a dog to go outside. My dog will also go outside and I trained her to go outside by bringing the urine pad outside and she understood to urinate or defecate in the grass because I put the pad in the grass and she knew to use the pad and understood to use the grass too. You can use a litter box and train her by placing her in the box and praising her when she urinates or defecates in the box. If you find her urinating or defecating out of the box, quickly pick her up and put her in the box. Be sure to praise her when she uses the box. If she defecates out of the box, pick up the feces and place them in the box for a while so she gets the idea to use the box. It should go pretty easily for you. I hope you have fun with your new dog and please let me know if you have more questions about this.