It depends on what kind of skill level you are trying to achieve. Some people are able to learn basic cooking skills in a matter of days. Some people take months to learn how to cook. Others may need to wait for years.
The time taken to learn to cook will depend on who you ask. One example is that someone who has never tried cooking before would likely take more time to learn than someone who cooks often. You may also need more experience with certain types of cooking than others. Baking requires more knowledge than frying.
If you want to learn how quickly you can cook, you should focus on learning a specific technique. After mastering one technique, you can move on to the next. Do not worry about how long it takes you to learn how to cook. Enjoy the process and keep practicing.