Do I need to change the status of my green card from employment to marriage and can I work for another employer?

With your "Green Card," achieved through an employment-based application, you became a Lawful Permanent Resident and there is no need for you to file any additional applications or to update your records with the USCIS in any way other than complying with your continued obligation to notify the USCIS of any new residential address within 10 days of moving (that process is through filing a Form AR-11). The time with which you needed to wait in order to apply to become a naturalized U.S. citizen was reached in December, 2016 - as early as 90 days before the end of five years from the date you became a Permanent Resident, and so you already may be eligible to apply to become a naturalized citizen. In that application process it will be necessary to reveal that you now are married and to provide information about your U.S. citizen spouse, and of course there are many additional details that impact eligibility for naturalization. The Republican Administration's January 27, 2017 Presidential Executive Order initially included a travel ban on even Permanent Residents from listed countries, and that highlights some of the security and additional benefits of being a U.S. citizen over being a Permanent Resident. The naturalization application process can be significantly more complex than it first may appear, and it would be wise for you to consult with an immigration lawyer.