in fl i won a judgement against my x for child support, now he has filed a motion to vacate the judgement can i respond to the court what do i do to stop or oppose his motion

Start by unlocking your caps button, looks like you are yelling at us. You can and should attend the hearing on his motion.

I guess my question is after you won, means you spent the time and trouble to file and go to court, why would you merely give up and allow him to take it all back ? Next why and on what grounds did he file the motion

OH SO I SEE NOW YOU REALLY MEANT TO BE YELLING AT US, THANKS FOR THE REDDIE. Your response is to attend the hearing and verbally tell the judge why your ex should not prevail.

With the limited information regarding your case; yes, you need to file a motion in response to vacating the judgment. I kept reading your question and it finally dawned on me perhaps you were not served with a court date for a hearing. Depending on your state law you may have a year to respond but of course immediate response is best. Internet is your best friend to answer a lot of your question for your state law and call a local attorney or several attorneys and ask questions. I know from experience sometimes you don't even have a hearing unless you file a motion for a hearing on your own behalf. Good luck and kudos for you going all the way for your kids.