trying to start a car that’s been sitting for years

I have a 1994 Oldsmobile Cutlass Supreme that has
been sitting outside my grandmothers house for
years (last time inspected was 2010 but was driven
after) we just put some fuel treatment and put in a
battery today. electricity works fine (radio, locks,
lights,etc.) but it won’t start. it turns over but won’t
start. we tried jumping it and such but still no luck. I
took a video of what it does, but sadly can’t attach.
just need some advice on how to get it started.