You will have to bring an application for the rescission of that judgment.
To succeed with such an application you must have a bona-fide defence against the claim.
Not having sufficient funds to pay the debt when the judgment was taken is strictly speaking not a bona-fide the defence, but most courts will still grant the application for rescission despite this, especially if the creditor doesn’t oppose
After the rescission of the judgment the credit bureau should rectify it’s records and you will once again be able to apply for financing from financial institutions.
We recommend that you consult an attorney to assist you with the rescission. He will need the case number, the parties, the name of the attorneys acting on behalf of the plaintiff/creditor and the name of the court where the judgment was granted.