There are a couple of things that could happen. The court could garnish the person's wages. That means the money would come out of their paycheck. They could also go to jail.
Check you state's statutes. If the respondent does not pay, you can seek to garnish their wages, or in some cases, have a lien placed on their property.
A judgment is good for twenty years, so you have twenty years to collect. You can either garnishee their wages or levy on property. It will be up to you to find out where the person works and get a garnishment against their wages. If you choose levy, the property is sold and you get your money out of it.
The next thing that you could do is go back to court and place a black mark on their credit, other than that, there is not to much that you are able to do.
You can ask the court to order them to come into court and list their assets and income under oath. After that, you can seek to seize their assets or garnish their wages to satisfy the judgement.