Start your maintenance procedures by dustless sweeping the floor completely to remove all grit, dust, and litter which you do not want to grind into the floor under a scrub pad. Microfibers will grab and hold even fine materials. If you choose to use a vacuum, make sure the parts hitting the surface are smooth and cannot scratch.
There are special pads available for terrazzo maintenance and you need to research with your supplier what best to use. Again, I would recommend an autoscrubber with the proper pad and a neutral cleaner. Do not use any acids or highly alkaline cleaning products which can damage the floor.
Use a light pressure on the pad(s), mop up any spillover from the squeegee, and enjoy as maintenance-free and eco-friendly a floor as you can get.