How Can I Learn to Code from Scratch?

I've been thinking about improving my coding skills and I recently read a post that inspired me to reach out for advice. I'm looking for resources or strategies that can help me learn how to approach problems before I start coding. Specifically, I'm interested in understanding the thought process behind writing code from the ground up. I've been working as a developer for about three years now, but I've leaned heavily on AI tools like ChatGPT. When I try to tackle problems on platforms like LeetCode, I often feel out of my depth. I typically input my solutions into ChatGPT, but the explanations I get often seem impractical. I'm trying to focus on the theoretical aspects of programming; any recommendations would be greatly appreciated!