When learning to program a new processor in Assembly Language, understanding the instruction set architecture (ISA) is crucial. The ISA includes registers used for storing information, with some designated for temporary storage. Processors also have memory areas like flash memory for programs and RAM for variables. Input/output devices (IO devices) allow communication with the outside world, from USB interfaces to LED controllers. Processors like the Cortex M family operate using Assembly Language instructions tailored to the hardware architecture. The design of a processor affects its performance and optimization for cost or power consumption. Embedded programming often involves both high-level language and Assembly Language coding to interact with the processor's hardware efficiently.