You install adb from Google and run one command. That's how you unlock a bootloader. As for root, yes you have to install something which is Magisk which is op

You install adb from Google and run one command. That's how you unlock a bootloader. As for root, yes you have to install something which is Magisk which is open source and vetted and had been around for around 5+ years. My wife that has never done it just did it for her new pixel 4a a few weeks ago. All I did was direct her to a step my step tutorial (I vetted the tutorial) and she did it flawlessly.