I'm defending my dad's small business and need help.
These cases are very difficult to defend. I would try to settle.
Although you don't indicate the alleged violations, I suspect they have to do with lack of van accessible parking and/or accessible restrooms. As such, you will probably have to try to settle it soon, rather than defend the lawsuit.
You might find these guides helpful:
http://www.avvo.com/legal-guides/ugc/myths-misconceptions-and-solutions-regarding-ada-accessibility-lawsuits-in-california?ref=kb_serp_title_1
http://www.avvo.com/legal-guides/ugc/practical-considerations-for-defending-an-ada-accessibility-lawsuit-in-california?ref=kb_serp_title_2
http://www.avvo.com/legal-guides/ugc/ada-accessibility-lawsuits-and-californias-sb-1608?ref=kb_serp_title_5
http://www.avvo.com/legal-guides/ugc/accessibility-under-californias-unruh-civil-rights-act?ref=kb_serp_title_6
http://www.avvo.com/legal-guides/ugc/accessibility-under-californias-disabled-persons-act?ref=kb_serp_title_7
http://www.avvo.com/legal-guides/ugc/accessibility-under-california-building-standards-coderegulations?ref=kb_serp_title_8
http://www.avvo.com/legal-guides/ugc/accessibility--awarding-attorneys-fees-under-unruh-civil-rights-act-in-california?ref=kb_serp_title_9
http://www.avvo.com/legal-guides/ugc/accessibility-under-californias-sb-1608?ref=kb_serp_title_4
I suggest you seek the assistance of a CASp.
http://www.avvo.com/legal-guides/ugc/accessibility--what-is-casp?ref=kb_serp_title_3
