In the era of rapidly evolving technological advancements and the growing importance of 21st-century skills and environmental consciousness, education systems face the challenge of providing personalized learning experiences that cater to individual student needs while fostering critical thinking, problem-solving abilities, and environmental awareness. This paper presents a formal model for personalizing learning paths through the integration of artificial intelligence (AI) into in- structional planning. The proposed model accounts for varying difficulty levels in learning activities related to 21st-century skills and environmental care, creating a comprehensive framework for optimizing student learning paths.