If you know where the other party works, then you can request that the clerk of the court issue a garnishment of wages. If you know where the other party banks, then you can request that the clerk of the court issue a garnishment other than wages. The Maryland Rules contain the specific requirements for those requests. While I would recommend that you seek the assistance of a lawyer, if you cannot afford one or do not think that the expense is warranted given the amount of the judgment, you can go to the law library in the Circuit Court and ask the librarian to show you the rules. Additionally, there is a pro bono law clinic in the Circuit Court on certain days. You may ask the Family Law Clerk to tell you the times and days and you may get some assistance.
Please be advised that any information or advice given herein does not constitute an attorney client relationship. Further, before taking any actions or deciding not to take any actions, you should seek counsel of an attorney. This forum cannot provide you with the anyalysis and detail necessary for a full and accurate opinion to be rendered.
You do not say but I suspect your judgment was with respect to child support. If so, take the judgement over to the Office of Child Support Enforcement. If proper, they will open a case file and pursue collection on your judgment on your behalf. The OCSE has all the resources of the state so they can reach much further and with greater enforcement than you could do otherwise - and at no cost to you.