If you're looking for a meeting place or a good stop around ½ or halfway between Campinas and Guarulhos, you can try Cajamar, Brazil, which is almost an hour southeast of Campinas, or almost an hour northwest of Guarulhos.
About ¼ or a fourth of the way, you can stop at Louveira, Brazil. This is about half an hour southeast of Campinas.
About ⅔ or two thirds of the way, you can stop at Caieiras, Brazil. This is almost an hour southeast of Campinas, or about half an hour northwest of Guarulhos.
If you drive straight through without stopping at all, the total distance is 110 km. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 1 hour, 29 minutes.