How to start learning machine learning from scratch

Answer 1

I prepared a code with handy materials helping to start learning ML, check it out:
https://code.sololearn.com/W2nvcMqTRi4q/?ref=app

I truly recommend Machine Learning course at coursera.org, taught by Andrew Ng, as an intro.

Answer 2

Those topics should be read in the book, there's a lot to cover and explain.
you should be able to code to start, at least can read a pseduo cose. Also Math taught at school never forget them.