One example of bad design is Information overload. If you want to learn any skill for free, this problem will often exist. It’s not limited to UI design only.
Internet has allowed people to learn any skill for free. They still pay to learn the skills they want to excel in. Why? The information provided for free is scattered around the internet. It’s really difficult for a new person to organize that information and get feedback from an experienced professional for free.
The following 5 practical exercises might help you learn UI for free.