To safely start a new fitness regime, begin with a thorough health assessment to identify any potential risks. Set realistic goals, focusing on both short-term and long-term achievements. Start with light exercises and gradually increase intensity to prevent injury. Consistency is key; aim to engage in physical activity at least 3-4 times a week. It's also important to incorporate a mix of aerobic and strength training, to optimize results. Finally, listen to your body to avoid overexertion, and consider consulting a fitness professional for guidance.