Learning to draw manga can vary greatly. If you practice consistently and have some basic art skills, you might start seeing improvement in 6 to 12 months. But to become really proficient, it could take several years of study and practice.
It really depends on your dedication and natural talent. Some people can pick it up in a few months, while for others it might take a year or more.
The time it takes to learn to draw manga varies from person to person. It can range from a few months if you're a fast learner and put in a lot of hours each day, to several years if you progress at a slower pace and have less time to devote to it.