Reinstalling ANY OSX would be a blessing

I have this older mac book pro maybe 2011 that has the cd drive and intel based . But I did something wrong of course when I tried to start fresh and actually followed the steps to get it ready to sell and now after 3 yrs I am sitting here going through the same steps of disk utility which to me is the most ridiculously confusing and random pressing of erase repair , and I’m ready to now crush this thing because out of all my years of being a loyal apple girl, not one option has worked and I’ve excepted the fact I must have erased something major but there is no hard drive, no Time Machine back ups, cannot install specified network not found or whatever that error was but it doesn’t make sense there was no warning that I erased something so major that I can never use this thing again: seriously I don’t care about losing data I just want the machine to turn on and load , this tedious hit or miss on what to erase or restore is not helping and why has apple not found a way to simply now connect the iPhone to restore my computers ability to reinstall using the iPhone as the device to fix it z!? Can someone just do that , this is really insane to go through this for 3 yrs and the randomness of troubleshooting techniques is completely insane and just so intricate. It’s a mac book pro it shouldn’t be this time consuming every other issue is in a nice error bubble saying what’s wrong. Just please come up with a new ability to fix this by plugging in my iPhone to be the savior but ohhhh I forgot now the iPhones have USBc now so that won’t work out. I give up , I can’t afford to service it and everything is functioning but I can’t install a basic os after following the directions everyone’s saying to do. Meanwhile I can never afford to buy another , please there should be a simple fix to this or invent a reinstalling using the iPhone as a simple fix for those of us who lose hours trying to fix something that everyone seems to have answers for but doesn’t work. Ok I’m done. 😩