Truck will not start

This truck is my dad's. But hes unable to work on it so I'm doing my best to help. This is what I've tried so far: new battery and cleaned terminals, replaced the fuel pump and checked all fuses, (I'm missing one that I cannot find a photo online for it's in the interior drivers side fuse panel the top only shows 2 fuses or relays and I have the power 30 amp in but the one next to it is missing and I don't know what it looks like to get a replacement), besides that though I cleaned the tank when I dropped it and replaced with new fuel. I've checked spark plugs and timing and timing is correctly done but it's just me doing this so I'm not sure I'm able to check for spark correctly. When I turn the key all lights come on, as well as check engine and battery and oil lights. I've checked all fluid levels and colors and all are fine though. When I turn key to start position nothing happens. Nothing at all. Lights don't dim. No click. So I jumped the starter relay under the hood and the starter cranks but still no engine start. What do I do next? I bbn plugged an odb reader in and tried 3 times each time it said cannot connect to vehicle.