Contact a lawyer if you can
Before you do anything else, contact a criminal defense attorney to discuss your case. Many defense lawyers will meet with you to discuss your case for free or a reduced fee. If you meet with the lawyer and you are unable to retain them, go to the next step
Put yourself on calendar
Contact the calendaring department in the county that your warrant was issued. You can do this by going to the department in person or by writing a letter. Ask them to put you on calendar. I have never heard of anyone getting arrested in the calendaring department so you should be fine putting yourself on calendar.
You will have a warrant
Even if you put yourself on calendar, you will still have a warrant until you go to court. You should contact a bail bondsman to discuss securing bail for your first court hearing. The judge may remand you on the first court date, having a bond in place may prevent you from having to go to jail.
Contact the public defender
If you could not hire a lawyer and you have put yourself on calendar, you can try to contact the public defender's office. They may not speak with you because they have not been appointed by the judge yet. However some public defender's offices will allow you to speak to a lawyer before you have to go to court. This may allow you to be more prepared for your first court date.