How to change nursing home under Medicaid and not resulted as denial from going into one again?

My Mom just admitted to a Nursing Home around 4 days in San Jose CA under Medicare and Medicaid. Before Admission, I was told that if we refused after their approval, if we decided not to go, then my Mom can never go to any Nursing Homes in the future, and other facilities will not accept her. Since there is lots of NH are full with waiting list and this NH had openings and they enforced us to move in within 3 to 5 days after their approval, so I did not have time to think it over, just needed to take the opportunity. And I never experienced with NH before but I am uncomfortable on certain things there already, so is it ok to switch or change her to a different NH if there is any better NH available later and how? Or anything will affect acceptance of my Mom to go to other NH in the future? I also like to try to get one good nursing home closer to my home to help me to visit her easier? Also I heard lots of bad things about NH which really worries me. Even my Mom is 89 years old but she is not at the late stage of dementia, she has good appetite and is still walking ok but slowly; and this nursing home has mixed stages of dementia people, some are with illusion and metal problem pretty bad talking frightening things like prison, stealing etc..., some are all not capable.... I really worry that my Mom will be affected. The reason for me to make the decision for her to go to NH, I was advised by friends, doctor etc. for her safety since she has been living by herself in a very small studio which is far away from me in San Francisco, an hour to 2 hours drive from my home, no relatives, no friends around; and she only has a caregiver for 3 hrs only, basically just cook 2 meals which split one to the evening, no activities, no going out and anytime she may go out if her brain changed, basically she was having bad quality life...but I heard bad things about NH too and I cannot afford those expensive NH which of course those are better; and I also cannot accommodate her in my house due to lots of reasons, and I am not trained to take care of dementia patient; it has been pretty heavy for me taking her to the doctors by going from Santa Clara to San Francisco for her doctors or any important needs and there's no parking at her area in San Francisco, it's costly and timely; and my Mom is pretty stubborn and insisted doing things on her way, even though she is kind of ok but lot of signs showed she does need help, like accidentally partying & making a mess more often lately, not remembering where to get her clothes/underwears/lots of other things, may use wrongs stuffs to do things. Other than my main question listed, any other good suggestions for my Mom's situation will appreciated. As she has been admitted to NH just a few days already but I'll keep her studio may be for another couple month to move her stuffs out or options if there is any?