P0303/P0304 and new P0507 after installing new IACV

There was no misfire codes before after installing my new sparkplugs and was told to install a new IACV (idle air control valve) because the car was constantly revving 1500 rpms to 2k rpms.

I already swapped the ignition coils around, installed new injector o - rings, new throttle body mounting gasket, and added new coolant but didn't flush the old one out and now the exhaust has white smoking that smells like burning fuel.

- also did an oil change

- please if someone could respond and help, I am losing motivation for my first project car