How do I get my van to start when the battery wont charge ?

So my battery went dead and idk why I bc it's a 34A
and it was fine before it went to impound and
came bck home with it and let it sit. It was at 11%
so my friend took it out bc the alarm would go off
in the middle of the night and then the next night
the lights would flicker in the night out of nowhere
so took it out before we did had to remove the
fuse box thing above the battery first for couple
day while I was looki for a different one did t have
the money for new. So ended up putting old one
back in and trying to charge it or jump it and it
would only get bck up to where the light in dash
board would come bck on and wipers would keep
goi g back and forth even when they weren't turned
on but wont charged wont start. Did I reset my van
and half to retrain it after I get the computer tool
hooked up n all that?? I am homeless and I rely on
my van. I need to get some information bc I'm not
safe. Plz lemke what I need to do