Was running shut off few days later it wouldn't start

Check the alternator also. If it checks at 12.5 volts, you can still use it. But start saving for a new one.

Does it crank, or fail to crank
if it cranks ok, (fast) and dont start say so...
:wont start means zero !

if it wont crank, jumper cable start it.
x2 if starter is dead, clean battery terms first.
this is always first if starter motor fail to have full power and sound like it does and see crankshaft spin at near 300 RPM.
that is first.
cranks ok but wont start is a few other tests.
my guess, you had a light was left on and drained the battery
rested battery voltage is 12.6v..
we dont have battery caps in USA, so avoid the acid bath trying that.

Check battery condition and connections (dirt, corrosion, tightness, acid level) to start with.