6gen won't start after it has been sitting for a month Options

[gts4]

2.2l, 5sfe. Battery has yellow and blue corrosion or build up. Almost looks like dry foam. I used booster cables with a new car and tried a battery pack. I could get the interior lights on, but when I try cranking the engine I get nothing.

Ideas?

I've had the starter, alternator, and distributor all changed within the last year at different times. Could it be the fuel pump? I recently added my own gas with a canister right before I grounded it. Lastly, could I flood the engine by trying to turn it over too often when nothing happens? How can I diagnose this? Should I clean the battery terminals and try again? Should I change the battery altogether?

I'm thinking of keeping this in my collection instead of selling. So before I replace the fenders, doors, and hatch I'd like to make sure she's running perfectly. Thanks.

[Roadrash]

when you say "nothing" do you mean absolutely nothing? you turn the key and nothing at all? or does the engine crank but not fire? or is there a clicking sound? do the dash lights and door dinger go out? Sounds like a battery to me, with the info provided. Take the cables off and clean them and the battery posts with some baking soda and water and a brush. Once your positive the cables have connection to the battery either jump it or put a battery charger on it at 2v until its charged. That's the first step