Check engine light

Good Afternoon;

I did a diagnostics on my car and the follow results came up and I need to know the best way to fix them, as follows:

P0116 Engine Coolant Temperature Circuit Range/Performance Problem

P1238 Fuel Pump Secondary Circuit Malfunction

P0506 Idle Control System RPM Lower Than Expected

P0155 Oxygen Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

P0121 Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance Problem

What parts do I need and which is the most important one to fix.