You will need to file a memorandum of points and authorities in opposition to the motion. It is due nine court days prior to the hearing on the motion. The arguments to be made will depend upon what the motion argues. My assumption is that your answer fails to deny the material allegations of the complaint, or make admissions.
You are going to lose the case if you don't have an attorney to file the opposition.
This happens every day, that people file papers in court in response to the debt collection lawsuit, but they lose anyway, not even getting to trial. I wrote a detailed blog about this, because I was appearing in court and there were two separate cases (at least) for that one morning in the courtroom where the debt collection law firm filed a motion for a judgment without any trial.
You can oppose the motion with (a) an explanation of why your answer was valid for the case, (b) you can ask for leave of court to amend your answer to correct the defects, OR (c) you can try to do both of these things. It might not be too late to have an attorney represent you.
Please see my response to our other question. Going to the Case Management Conference doesn't mean anything -- that's just a scheduling conference. If you can't raise a triable issue of fact in your opposition to their motion, then the creditor will be entitled to summary judgment against you and there doesn't need to be a trial to try any disputed issues. This saves the litigants effort and money, and saves the taxpayers judicial resources.
I'm not sure fighting this makes sense for you anyway - are also liable for the creditor's legal fees, in addition to the debt they're suing for? If so, then a trial just adds more fees to your debt, and you might also be prolonging acrual of interest at the credit card's presumably very high rate, rather than the 10% post-judgment rate.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.