Should I continue to use python while learning the programming fundamentals and switch languages after I mastered the basics

I started to learn python but I realized that JavaScript might be better suited for what I wanted to build, do I stick with python? Or should I master the remaining of the basics in js (The basics that I have yet to master are classes and oop)

You can master the basics in any language. If you want to use Javascript for what you want to build, there is no harm in switching over to Javascript now and covering the basics again. You will have to eventually. (this time will probably be faster)

Yes, if you feel like JavaScript would be better for you, definetly switch. You can always go back to python if you want to.