I think my neighbor might die soon and it's kinda my fault.
How is your neighbor dying soon your fault?
I kinda tripped him on his way to the grocery store.
Falls can be dangerous and even life threatening to elderly people since their bodies do not heal very well with advanced age. If you tripped your neighbor that is very bad as neighbors are supposed to help out one another and not cause any harm. You should apologize for tripping your neighbor and help him make a healthy recovery as best that you can.
I'm going to sue him.
Suing your neighbor while they are still recovering is pretty messed up. You should own up to tripping him and causing him to be in fights for his life.