String theory has never made a prediction that has come true and gets disproven each time we build a bigger particle accelerator and discover new particles. Like the theory can't even explain basic observations about particle physics and the universe. The String theorists just keep telling everyone that it will work out bro, trust us, give us more funding.
Like the only reason it hasen't been abandoned yet and is still weirdly popular is becuase of the perverse incentives in academics where it pays more to pursue this kind of groundbreaking nonsense than trying to advance the frontier of the established and boring Standard Model. And it's easy to be groundbreaking when you are just making shit up. Just think of the millions in research funding these charlatans have scammed from us. They have played us for absolute fools.
We need to round up all the String theorists and parade them through the streets with dunce caps, Cultural Revolution style. We need to do 70 hour struggle sessions against them until they pass out from exhaustion.
"Particles are actually tiny strings that wiggle" "There are 11 dimensions but you don't notice the extra ones cause their are too small" - Statements dreamed up by the utterly deranged.
Where do you go after watching their hundreds of videos?
To get an understanding of it that doesn't rely on analogy and metaphor you have to delve into the math, there's no way around it.
If you want the typical undergrad courses, Leonard Susskind has videos of his classes up on youtube. Don't worry that they're 10-15 years old, the basic math hasn't changed. The video quality does improve as they go though.
If you want a more self-directed approach, Roger Penrose's book The Road to Reality is a good resource and provides more of a roadmap. Also if you want to see Jordan Peterson utterly embarrass himself, watch his interview of Penrose.
road to reality is great but not for the faint of heart. Took me 9 months to get through it and I did maybe 25% or the excercises and was familiar with most of the introductory math.
I'd recommend brushing up your calculus to 1st year university before diving in.
If you have a few months to spare:
Classical Mechanics - https://www.youtube.com/watch?v=GtOGurrUPmQ&list=PLyQSN7X0ro203puVhQsmCj9qhlFQ-As8e&index=2
Electricity and Magnetism - https://www.youtube.com/watch?v=x1-SibwIPM4&list=PLyQSN7X0ro2314mKyUiOILaOC2hk6Pc3j&index=2
Wave Mechanics - https://www.youtube.com/watch?v=VuX_UExHa0M&list=PLyQSN7X0ro22WeXM2QCKJm2NP_xHpGV89&index=2
Quantum Physics - https://www.youtube.com/watch?v=lZ3bPUKo5zc&list=PLyQSN7X0ro21XsVfRHhiWGEEJigdjpF3s + https://www.youtube.com/watch?v=QI13S04w8dM&list=PLyQSN7X0ro21y1VjcdTi5jbpH26O-Tk68
That is absolutely as far as you can go without getting into hardcore maths.