How do I obtain the police report for a DUI that I got?

At any arraignment (initial hearing) you should be able to get any police report and accompanying police officer narrative.  You can get a copy of the police report from the police or sheriff's department records office in advance of the arraingment, but it may only have a brief report and not the accompanying narrative. 

The narrative is the most helpful part for your case, but you may have to wait to get it.

Initially, you will only recieve a Criminal Complaint and Affidavit of Probable Cause. After your preliminary hearing and subsequent formal arraignment, your lawyer will get the police report as part of discovery. You are not entiltled to it before your formal arraignment.