You need some fluency in python and basic knowledge of algebra (matrix multiplication etc.)

If you want, you can also start with the first lessons of course.fast.ai

Getting started with it takes exactly zero experience. Being productive in it does, but that's unrelated to the starting point, and shouldn't discourage you, if you really want to do it.

There are several open courses, online.

Yes. The journey will teach you everything you need to know or it'll kill you. The likelihood of that happening here or any path in IT is negligible at best. So just show up everyday and collect more fuck ups than the next guy (or your former self).

The tools are basically irrelevant conceptually. Its all about the mathematics

It might make sense to get a handle on Python first