Campinas is a large, spread-out city built around cars, and getting around without one requires patience. The city has a metro system — officially the VLT (Veículo Leve sobre Trilhos), often called the Metrô — but it is limited to a single operational line with a handful of stations, which makes it useful only for specific journeys. Extensions have been planned for decades. The bus network is extensive but can be difficult to navigate without local knowledge.
By app-car: Uber and 99 are both well established in Campinas and are by far the easiest way for a visitor to move around. Fares are reasonable by European or North American standards. This is the practical choice for getting between the Cambuí neighbourhood, the city centre, Parque Portugal, and Unicamp.
On foot: The Cambuí neighbourhood and the historic centre are walkable within themselves, though the distances between them are long enough that most people take a car. The city centre is compact and manageable on foot during daylight; less so at night.
By car: If you are spending several days in the city and plan to visit outlying sights, renting a car is worthwhile. Parking in the centre is metered but usually available. Traffic is heavy during rush hour on the main arterials.