Legal Question in Criminal Law in Maryland

You could, but you will still have to appear and request conyinuance on your trial date. The clerk's office has no authority to continue. Only a judge may do that, and the state has a right to be heard about it too.

If this is the first trial date, and if you were not previously advised of the right to counsel by the court, for instance during a bail review, then your chances are good that the case will be continued. Good luck.

No you need to file in writing at the Clerk's office. But meet with a lawyer first, and put that fact in the motion, it'll be more likely to be granted.