thank you for sharing your question with us in the community.
As for your question:
1. in order to able to move, you need to find a job or Ausbildung there.
2. As for the apartment- you have to do it by yourself- but try the website: www.wg-gesucht.de
3. In regards of the financial support if you ahve a job and cannot support your family entirely the jobcenter will assist you, however you will have to find a job that pays at least what your are getting now.
I hope I could assist you with your question and should be there further questions please do not hesitate to use the community.