Where to learn ?

I want to find a website where I can learn all about math, pre algebra, algebra, calculus, geometry, statistics… everything

I need it to be free since what I’ve encountered online needs a subscription

Context: early 20s, current academic level is Master’s in a scientific field

Reasoning: math has always been a little bit scary for me and I want to start from the very beginning in order to feel more confident, id love something interactive and not just lectures, getting to do exercises and placement tests etc

Author: horror-spaggheti-270