How would I find a case number to a case that's already been filed?

You need to know the Court where the case was filed. Federal or State, and, if State, in what county? Once you have identified the Court, the clerk...

I'm being supenaed as a witness but I intentionally refuse to open the door for the serve to deliver the subpoena.

Your reluctance is understandable, but - if you are served and don't appear, you could end up being fined and/or jailed for contempt of court. Have...

Do you think I it is impossible to get a different answer in a civil suit in a county court than you did in a JP court?

You can certainly get a different result in County Court, but probably not representing yourself, particularly if the seller has an attorney. One...

A lawyer cannot "file" a motion unless the lawyer is representing someone. The question is whether a lawyer can write a motion that a party then...

I would like to file a Motion for Dismissal form with the court for a lawsuit that should not have been filed.

From the question it sounds as if the lawsuit was filed against you by someone else in San Antonio. If you have been "served" with the petition...