Here is what the Ford manual says about your codes:

P0122 - Throttle/Pedal Position Sensor A Circuit Low
For Vehicles With Electronic Throttle Control (ETC)
Description: The electronic throttle control (ETC) throttle position (TP) sensor 1 circuit was flagged as a concern by the powertrain control module (PCM) indicating a low voltage or open circuit.
Possible Causes: Open ETC TP sensor harness
Short to ground in the ETC TP sensor harness
Damaged TP sensor
SIG RTN circuit open to the TP sensor

P0171 - System Too Lean (Bank 1)
Description: The adaptive fuel strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. Refer to Section 1, Powertrain Control Software Fuel Trim for more information.
Possible Causes: Fuel System:
Damaged or leaking fuel pulse damper
Fuel filter plugged or dirty
Damaged or worn fuel pump
Leaking fuel pump check valve
Leaking/contaminated fuel injectors
Low fuel pressure or running out of fuel
EVAP canister purge valve is leaking when the canister is clean
Fuel supply line restricted
Fuel rail pressure sensor bias
Air Induction System:
Air leaks after the mass air flow (MAF) sensor
Vacuum leaks
PCV system is leaking or the valve is stuck open
Improperly seated engine oil dipstick
Exhaust System:
Exhaust leaks in the exhaust manifold gasket or mating gaskets before or near the HO2S
EGR System:
Vacuum hose disconnected on exhaust gas recirculation (EGR) system module (ESM) applications
EGR valve tube/gasket leak
EVR solenoid vacuum leak
Secondary Air Injection:
Damaged secondary air injection system or a mechanically stuck valve
Air Measurement System:
Damaged or contaminated MAF sensor

P0174 - System Too Lean (Bank 2)
Description: See the description for DTC P0171.
Possible Causes: See the possible causes for DTC P0171.
Diagnostic Aids: See the diagnostic aids for DTC P0171.

P0300 - Random Misfire Detected
Description: The random misfire DTC indicates multiple cylinders are misfiring or the powertrain control module (PCM) cannot identify which cylinder is misfiring.
Possible Causes: Camshaft position sensor (CMP)
Low fuel (less than 1/8 tank)
Stuck open EGR valve
Blocked EGR passages

Your possible problems are the TPS sensor (one you unpluged) and first listed code, the EGR system (a constant theme through all the codes except for the first) or camshaft position sensor/sycronizer. If it was making any belt slipping type sounds prior to the problem I would say the cps. Was your tank low, could be the fuel filter has gotten clogged with debris. Hope this gives you someplace to start.

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'20 Ranger Lariat FX4 Oxford White