…and here is another great channel, if you want to get an idea of modern number theory/ abstract algebra:
https://www.youtube.com/watch?v=IP7nW_hKB7I&list=RDCMUCW6TXMZ5Pq6yL6_k5NZ2e0Q&start_radio=1&rv=IP7nW_hKB7I&t=30
All the math here is explained clearly and accurately (and it will probably make your head spin, but don’t worry about that 😉 eventually things will start to make sense and you might become a magician yourself)