Serious n00b question: How the hell do you learn how to drive manual (specifically for sim racing)??

I've exclusively driven automatic vehicles IRL my entire life, and honestly I have 0 interest in ever driving a manual IRL. But for sim racing (and esp drifting) it seems pretty imperative to learn how to drive manual.

I know some of the basics, but are there any resources someone can point me to that sort of detail the "theory" behind driving manual? I get the concept of shifting to keep the engine within its maximum power band, but I don't understand how that translates to applicable technique.

I understand some techniques like heel-toe, clutch-kicks, etc. but I don't have any kind of mental map for the bigger picture of how to properly utilize the transmission.

I know I could probably just throw myself onto a course for a few hours/days and suss it out by feel, but I really prefer to learn some theory beforehand to avoid developing bad habits.

Thanks in advance <3