MY FUEL GAUGE READS ZERO EVEN AFTER FILLING UP

The FSM covers the test for this,read the FSM.
bad sender in tank.
bad wires from it to ...
the fuel gauge. (or PCM)

what we do is check the wire to the tank, unplugged.
and check the resistance, with a meter, 10 to 200 ohms is typical
if infinity the sender is bad.
if it reads good, we move to the other end of the wire.
still good? if all that is good then the guage is bad.
many cars have gauge self test. read the FSM for this.

2nd best. is Alldata.com

I would think that the fuel sender unit is not working , this is incorporated into the fuel pump , directly into the top of the fuel tank , i would get a mechanic to investigate as there are a few checks that can be made to determine where the fault lies before going ahead and changing the fuel sender