Car will not start

1) 1999 Mustang GT v8 manual trans. 39780 miles
2) purchased the car about two weeks ago from a guy who got the car from his dad
3) car had sat for a year in a garage
4) the day the guy dropped it off he said he had a hard time starting it that morning, he thought it was because the gas was very low. So he filled it with (1/2 ways) with 97 octane.
5) we shut it off and it started right back up no problems, I drove it for a mile seemed ok
6) parked it in a garage for 2 weeks, not yet registered waiting for title
7) tried starting it yesterday, turned over but would not catch, checked the battery the "indicator light" had turned red, so I charged the battery until the light went out and read full charge. Tried again same results
8) replaced all eight spark plugs, tried again same results, noticed that the battery had lost some charge, went to sears bought a brand new battery
9) car will not start !
10) did a OBD II scan no trouble codes came up?
begiing to think it may be a fuel issue (pump) what do u guys think, I fit is how does one check, I am a little handy around cars but not really a mechanic