How likely am I to receive jail time for a first offense?

I am not sure if criminal charges were filed against you or whether your girlfriend filed a domestic violence complaint against you based on terrorist threats, etc or whether your girlfriend  filed a domestic violence complaint and separate criminal charges against you for those actions but you need to meet with a family law specialist immediately. This is not a setting where you want to go to court to try and defend yourself without understanding the legal consequences of the charges against you. In retaining a family law attorney, he needs to review the actual complaints filed against you and read the underlying incident report[s] to know what you are up against and what is the best course of action for you to take. But, please do not ignore the seriousness of the charges against you and do not wait for the court to contact you. It is your responsibilty to contact the court to find out when the matter will be on before the court, so that you can be properly prepared.