The mouse you had for the old laptop should work, make sure it is turned on (underneath) and then go to the Bluetooth menu on the computer. It’s the little icon below second from the right on the menu bar. Go to Setup Device and hopefully it will find the mouse. That will get you by until you get something else.
If you like using the trackpad you can get an external one.
There is the Kensington Orbit Trackball (the ball is smaller than yours) and the Logitech Trackman Trackball.
On another note, I will be in your neighborhood this afternoon. There is an event at the Mass Maritime Academy for the launch of the OpenCape/CapeNet system at 1:30. If you are up for it I could stop and say hello afterwards.