superkret , 11 months ago

adb = connect your phone to your pc and send commands to it. Can do things that aren’t included in the Android user interface, but can’t touch the core system or give you extra rights. Necessary for the Universal Android Debloater and flashing custom ROMs.
root (most common method is Magisk) = gives you access to functions that are normally off limits. Its utility is overestimated if you just want to use your phone as a phone, but it lets you use it for purposes it wasn’t designed for. Not necessary for degoogling, microG installation or flashing custom ROMS.
unlocking bootloader = necessary for rooting, flashing a custom ROM or replacing Google Play Services with microG. Degoogling without a custom ROM and microG is possible, but a pain in the ass and limited in functionality. You want this.
custom boot loader (most common is TWRP) = necessary for flashing custom ROMS and installing microG.

If your phone is supported by TWRP or a custom ROM (look at LineageOS first), installing that is the easiest way to completely degoogle.
If it isn’t, then you can still root it, remove Google apps with adb and use Netguard to keep any Google apps you still need from phoning home. But getting push messages, location and speech recognition/synthesis to work in your apps is a crapshoot. You will probably be limited to the functionality of open source apps that don’t depend on Google services.