Need help with senior pom!

Hi, I adopted a 7 year old Pom from a lady yesterday but have several questions. Firstly, I have never owned a dog so I’m not sure what is normal so any help would be great. I adopted my Pom from a woman who said she didn’t have space for her since she had too many pets. She told me her Pom is 7, has no medical issues, and just gave birth 3 months ago. Upon arriving to my house I noticed that my Pom has fragile bones and sometimes stands weird with her arms flared out. She also sneezes a lot and pees everywhere even though I put puppy pads on the floor. When I took her out on a walk, she stays put in one place and I have to carry her a bit farther from my building to start walking. I feel like the woman lied to me about medical issues and only having birth once and want to take her to the vet. I was also wondering if you guys could advise me on how to potty train her. I bought diapers so she at least doesn’t pee on my floor and carpet during the night.