Every case is unique, but you should always expect that it will take months to resolve any case. In some complex felony cases it's not unusual to have the case pending for over a year or more. Misdemeanor cases in District and Municipal courts will proceed more rapidly but even then you should expect at least a couple of months or more. Your lawyer will be busy in the early part of your case gathering evidence and reviewing documents, before being able to engage in any meaningful negotiations with the government.
Even if you intend to plead guilty and get a plea bargain, it's important to allow your attorney enough time to convince the prosecutor that he is serious about fighting your case. Prosecutors don't like going to trial, and if your lawyer appears to be preparing for trial, you will sometimes get a better bargain from a prosecutor who wants to avoid having to go to trial. If your lawyer walks into court on day one and asks for a deal, the prosecutor may sense that there's not much of a fight ahead and will be less inclined to give a good offer. Trial is the primary negotiating chip in your lawyer's pocket. Let him get the full value of that chip by giving him the time to persuade the prosecutor that he's serious.
In most cases the warrant can be quashed or otherwise mitigated by your lawyer, so calling a lawyer will always be the first step to take in this process.