Basic Mods Questions- Unlock, Root, AdAway, Tether, TWRP

When I get phone I'm most interested in doing build prop edit for tether, installing custom recovery TWRP for 6P and AdAway would be nice. Loss of Google Pay not a show stopper. Would like to do OTA factory image updates or modified images until custom ROMs and Kernels mature.
Can someone please post idiot proof specific instructions or guide links. I know some basics but assume others do not.
Thanks