Paris has an excellent public transportation system, including metro, bus, and bike-sharing services like Vélib. A 3-day unlimited public transportation pass costs $28 per person. Taxis and Ubers are also readily available but can be more expensive.
If you have more time, consider visiting other popular attractions such as the Palace of Versailles, the Catacombs, and the Arc de Triomphe. If you have less time, prioritize your must-see locations and book skip-the-line tickets in advance to avoid waits. Don't forget to try some classic French dishes like croissants, escargot, and cheese.