Zero foundation depends on what kind of zero foundation you are. If you can use a computer, but you can't design a UI, it's ok to learn the basic knowledge of UI design through four months' study in a training school (which is basically four months in major training schools), and then find a job as a junior UI designer. As a novice UI, even when I arrive at the company, I mainly focus on accumulating experience, and don't care about salary. Second-tier cities have just come out, and the average can only reach 3 K. But if you don't study hard during the four months of training, it may be difficult to find a job after you come out.
If you can't even use a computer, copy and paste, or install software, then going to a training school is a waste of time and tuition.
Because UI design is not difficult to learn, you can learn it in four months. Coupled with the exaggerated publicity of major training institutions (and more than exaggerated), many people learn UI. Now the streets are full of UI designers, so you should carefully consider whether to learn UI.