It won't turn on

Why didn't the mechanic continue on & resolve the issue?

You don't have the experience to do so, as your here

No one can tell you what is wrong without the vehicle to test,
common sense

Fuel Pressure at Motor?

CLEAN & DRY ALL PARTS CHECK FUEL IS GOOD,ONLY IF YOU KNOW WHAT YOU ARE DOING PLACCE SOME FUEL IN CARB ,CLEAN & CHECK PLUG GAPS,A CAR STANDING WILL LOOSE THE PETROL ORIGINAL STRRNGTH

the fuel will be contaminated try putting some fresh in the carb clean all the ignition electrics just cause its turning does not mean it will fire,clean the plugs remove air filter,(just till the car starts) then replace service the car its a must

are you low on coolant ?

Safer is to use 'carburetor cleaner' which is also flammable but a little less dangerous than using gasoline.After sitting a long time, our modern gasoline gets tired; never allow something to sit so long without adding some 'fuel stabilizer.'If possible with your car, I would drain (siphon) the tired gas out and replace it with a few gallons of fresh.
Really tough starting problems can also be overcome with 'starting fluid' which is pure ether and very flammable.Any of these may require the removal of the engine air filter so the liquid gets into the intake manifold.
Stale gasoline can also gum up the fuel injectors which may have to be removed for service if none of the fluids causes the engine to fire.

My first thought is to check the fuel pump operation.
Check to see if fuel pump is getting power.

This is how I check the pump.

Usually there is an in-line fuel filter that can be removed.
While its removed...bump the starter to see if gas shoots out the gas line.
If not, there might be a clog at the pump...or the pump needs replacing.

Hope this helps...

probably something broken inside steering column

If i understand you right the truck has been sitting for two years.If it has been sitting that long without running or moving the gas has turned to varnish...I suggest that you drain and refill the fuel tank,and replace the fuel filter located on/in the frame rail on drivers side.

Disconect the battery and ECM for FOUR DAYS then reconect the ECM and BATTERY. Let it sit for another four days without turning anything on. It should start but will run rough for about 200 miles as the ECM relearns the system. I had the same issue and that is what fixed it.