You've made a ton of progress on this, but let's step back and go over what exactly you're doing, since pretty much all machine learning is built on the same linear algebra underpinning regression. It's best to build up from a strong foundation!
You can write markdown notes in Jupyter notebooks. In your linear regression notebook (which probably should have a descriptive name), try adding markdown cells explaining what you're doing in each cell. In particular, see if you can relate your code to the math in this paper.
You've made a ton of progress on this, but let's step back and go over what exactly you're doing, since pretty much all machine learning is built on the same linear algebra underpinning regression. It's best to build up from a strong foundation!
You can write markdown notes in Jupyter notebooks. In your linear regression notebook (which probably should have a descriptive name), try adding markdown cells explaining what you're doing in each cell. In particular, see if you can relate your code to the math in this paper.