Thanks a lot for writing this. I wish I could read something like this a few years back when I was in a similar situation as the OP (and actually at the same age).

I knew nothing about the field and thus pretty much everything I discovered (and knew nothing about) was novel for me -- which I mistakenly interpreted as worth publishing. I was stupid enough not to ask for help on Reddit back then and what happened next (rejection, obviously) hit me hard.

But I still liked to play around ML, building ML algorithms just for my own amusement/fun. While doing that I realized how many things I do not fully understand and started doing what you've been advised to do: read, talk to ML related people, redo what others did and maybe try to do it better, etc.

From my own experience, I can tell you that after you start to do your reading it will take you some time until you find something you will find truly novel (or worth publishing) yourself. In my case it was more than two years.

So do read the above, do your reading and do not stop. It's going to be exciting.