Start with basic shapes and proportions. Practice sketching eyes, faces, and bodies regularly. Also, study different styles of manga to get inspiration.
Well, first, learn the fundamentals like figure construction and shading. Then, build a collection of references from various manga works. And keep practicing, even if your early attempts aren't perfect. With time and patience, you'll improve.
To get good at manga drawing, you need to focus on anatomy, perspective, and expressions. Learn how to use lines effectively and experiment with different tools. Don't forget to observe real-life objects and people for reference.