The fact that you enrolled in a university that was later found to be a "sham university" would not necessarily make you inadmissible. To be inadmissible for fraud or material misrepresentation, you must have engaged in either fraudulent conduct or knowingly made a material misrepresentation. It is unclear from the information provided if you engaged in such conduct. Assuming you could be found inadmissible, you may be eligible for a waiver of inadmissibility if you can establish your spouse would suffer extreme hardship. I strongly encourage you to retain an experienced attorney to assist you with this matter.
You shouldn't need a waiver unless there are details that you're not sharing. You did enter the country legally?
As far as the school, do your best to comply with the officer's request and so consult with an attorney.
The information offered is general in nature and not meant to be relied upon as legal advice. Please consult an attorney prior to making legal decisions. Visit us at www.tunitskylaw.com. Contact us at 713.335.5505 or email at email@example.com. Veronica Tunitsky offers in-person, as well as telephone and email consultations.
If ou entered the country illegally, you would not need a waiver. However, you really should consult with an immigration lawyer who can assist you in procuring your green card. You will have to address these issues but a waiver may not be required.