Coding a class swapping system

The mechanic I'm trying to get to work would be the player runs around and can switch between 5 fighting styles but picking up different totems. Here is a quick example;

The player would start off without a totem and they grab a spear master totem, letting them use spears and level up a spear skill tree, eventually they find a Wizard Totem and switch to it letting them use spells and level up a spell skill tree. If the player comes across another spear totem they can switch back to where they were in the spear skill tree.

I was thinking of having a script for each individual fighting style that would activate while the player had a specific totem, either that or a state system where each style is a state (like how in mario he has racoon, grown up, and fire flower). Any kind of help starting this off would be great. Also, i intend to program in JS (most experience i have is with JS).