Need some help on figuring out whats goin on with my truck I have a 88 f150 was driving down the road an heard a knocking sound coming from down by my shifter then truck just died and now it won't start an have no idea why.

 

I think you need to supply more info on a 34 year old truck;
Mileage
general history of service
manual or auto transmission
engine info
last time spark plugs, wires were done
last time points & condenser were done

your trucks problem could be a myriad of directions but I’d be looking at the starter, maybe it “fell” off hence the knocking sound projected through the shifter

good luck