1998 Ford Contour #1 cyl poor firing

I just bought a used car for $1,400: 1998 ford contour automatic, 2.5 V6 24 valve DOHC 120,000 miles
(1) Battery was stone dead could not start the car even with jumper;
(2) With dead battery removed from the car, it jump started, and engine was running for half minute after jumper removed, but then engine stopped (does It mean alternator is defective/marginal?
(3) Shifts bad, from low to drive, RPM shoots to 8000 to 9000, and then red light with Battery sign on the dash glows briefly
(2) Inspection failure reports:
(i) #1 cyl firing poorly
(ii) Both Oxygen sensors sensing something not normal,

(ii) and some other codes.

my email: skmandal2003@hotmail. Com