I'm a CS grad and I still suck at computer architecture. Help.

In uni I did learn about CPUs, RAM, caches, memory hierarchy, etc. — but I focused more on building software (web/mobile/desktop apps) and never really used that knowledge. Now I basically know nothing again and get imposter syndrome whenever people talk about this stuff, even when it's just about buying a new PC.

Any beginner-friendly books, videos, or resources you'd recommend to refresh and rebuild my understanding from the ground up?