Situation= matched 15 amp breaker and outlets, new GFCI on new circuit, first GFCI in circuit, line to line load to load ground to ground, ground and neutral connect in breaker box through bars but not before, continuity between neutral and ground, no continuity between positive and ground, continuity tests the same to ground pole in GFCI, ground pigtail and ground screw on box, when the breaker is on this GFCI fails while all other outlets, including the GFCI's from same pack work ('upstream' and 'downstream'). What's the rip?
Get the GFCI working
Disconnect all the wires but ground to this GFCI. Get some tape and cover up the LOAD terminals, you will not be using them for awhile.
Now comnect the cable/wires from the breaker panel to the LINE terminals of this GFCI. Nothing to the LOAD terminals.
If there are any loose wires remaining, wrap them with tape or wire nuts.
Now test. If it doesn't work, fix stuff until it does work. Do not attach anything to the LOAD terminals. Do not pigtail or attach more than 1 wire to this one's LINE terminals. Do not go another step until this GFCI is working perfect.
If the GFCI is just plain broken, steal another one from a downstream receptacle on this same circuit.
Get the next receptacle working
OK, now take the tape off the LOAD terminals and hook up the other (downstream) cable to LOAD. Do not mess with anything else.
Go to the next receptacle in the circuit. Which cable is the supply from that first GFCI? Hook up only that cable's hot, neutral and ground to a plain receptacle.
Now test the first GFCI again, it better still work.
Test the plain receptacle too. It should work, and should shut off if you trip the first GFCI. Do you have a 3-light tester with GFCI test function? Good, use the GFCI test in the plain receptacle. Make sure it trips the first GFCI.
Did you have a GFCI receptacle in this second location? Get rid of it. Stay with the plain receptacle that is working.
Stick a "GFCI Protected" sticker on the coverplate of that plain receptacle. It is protected by the first GFCI because you hung it off the LOAD terminals.
Get the third working
I gather the second outlet also has a set of now-unhooked wires leading to a third receptacle? Hook those up to this second outlet, and move to the third outlet and repeat the above "second receptacle" advice above. Move down your chain one receptacle at a time.
You may end up with a few extra GFCIs if you overbought. That's fine. Use them on other circuits in your house, same deal, you only put the GFCI on the first one.