I would recommend starting with HTML and CSS and avoid JavaScript until you have a good sense of how the static stuff works. Then play a bit with JS and find a framework that you like working in.
If you already know Python it should be relatively easy to learn JS, just try to understand _this_, scoping and variable hoisting, which is the source of almost all of the weirdness of JavaScript and something a lot of (even experienced) developers get confused on.
Eventually it makes sense to learn JavaScript on its face. It is a weird and beautiful language. Abandon hope of understanding it unless you read a coherent book about it. As for me, I read JavaScript: The Definitive Guide from cover to cover. I have also read good things about JavaScript: The Good Parts, and I know that Douglas Crockford is smart.
I love React and would recommend it as the primary frontend library. However, I would suggest avoiding the Material UI component library entirely (as I believe it’s both difficult to customise and over-engineered) and just write SASS to start off.
If you really like how Angular 1 worked (writing templates instead of JS to represent DOM) then Vue is a great choice.
If you already know Python it should be relatively easy to learn JS, just try to understand _this_, scoping and variable hoisting, which is the source of almost all of the weirdness of JavaScript and something a lot of (even experienced) developers get confused on.