It could be a weak battery, bad connection, or a bad wire, or a bad starter.
Weak battery: Maybe it has enough power for windows and radio, but not enough to turn over engine. Try placing on a charger to boost. Or get another vehicle and try a jump start.
Check connections: First clean off battery and starter connections. Try staring again.
Bad wire: Check the resistance of negative and positive battery cables with a meter. If you don't have a multimeter, you can check your negative battery cable ground by jump starting your ford from another vehicle placing the jumper cable ground on your engine block ground instead of the battery post ground.
Bad starter: Connect your starter directly to the good battery. If it spins, its good. Doesn't spin, replace.
If this happened suddenly, I would suspect the negative cable wire from the battery to the ground.