Your research obviously does not include installing pop_os. The settings are in what you would call on Windows the “system tray”. The menu in the corner. You have some quick settings there, which includes the power profile. Then you can open the full settings app which has everything. Just go look for yourself.
Nobody said anything about wiping a hard drive. This isn’t rocket surgery. You can live boot from any old USB media laying around. (If having a second hard drive is too much to ask)