In Massachusetts operation of an unregistered vehicle is likely what your car with an expired registration was considered. This offense is listed in the Chapter 90 Section 9 of Massachusetts General Laws. Here it lists that a person convicted of a violation of this section shall be punished by a fine of not more than one hundred dollars for the first offense and not more than one thousand dollars for any subsequent offense.

Driving without a license, which you may have been cited for since your out of state license was expired and thus not technically valid, is a criminal offense as you mentioned. Massachusetts General Laws Chapter 90 Section 10 discusses this offense. Penalties are not mentioned here. The MA driver's manual though states you may face a considerable fine and/or jail sentence, as well as additional suspension sanctions if you drive without a license or on a suspended or revoked license.

Without knowing the exact state laws that you were cited for we are unable to give you more information on what your possible penalties may be. We would recommend that you contact the court listed on your tickets for driving with an expired driver's license and with expired car registration to see what penalties you may face. It would be worth telling the clerk of the court that you now have registered your vehicle in MA and have obtained a MA driver's license to see if this may help you get your penalties reduced or even perhaps your tickets dismissed.