What do I need to focus on?

Source: Dev.to

Question

I would like to be a full‑stack developer and someone who can disassemble and assemble computers—from the monitor to the motherboard. What should I focus on to make this dream a reality? I know a bit from both ends; I am still currently learning full‑stack development, but I am also interested in the hardware side. I know simple hardware tasks like removing and installing a battery, swapping an HDD for an SSD, and cleaning internal components.