The great paradox: to truly know what there is after death, you must first die, and there's no returning from that AFAIK.  Anyone who tries to sell you on something different is full of it.

As far as anyone can actually tell, what's left after death is what you've done in this world, i.e. your legacy.  Most people are completely eradicated from history, they have no names, no faces, only a lineage if that; very few people are worth remembering, and of those who are remembered, are often not even known by most people: you are fortunate to be remembered by anyone long after your death, and sometimes it's just for infamy; I'm sure Hitler didn't want to be remembered as a villain but alas.

If you want to be remembered, you have to do something great.  Everyone knows who Mozart, Bach and Beethoven are, and everyone knows why they are remembered; everyone knows Plato, and Socrates, and Aristotle, though they may not know precisely why they stick out--these guys are several thousand years old and their works are still studied.  I could go on.

As far as anyone can actually tell, the conscious is tied to the passage of time and the senses as perceived by each individual; our thoughts and feelings are a stream, one after the other, and that is who we are; I can say these thoughts are mine, but once I die, I lose the ability to recognize these thoughts are mine and the ability to recognize that I have the ability to recognize these thoughts are mine, and of course I lose the ability to have thoughts at all.  If the conscious is tied to the mind and the mind perishes upon death, and if the world exists outside of our ability to sense it, then one can conclude that the world will continue on without this one eye in the galaxy to perceive its happening, and perhaps perceive this one eye posthumous too, as we perceive other eyes in our history.  Where can the consciousness go without its shell to generate the stream of "me"?--if the ego is tied to this shell and the shell perishes, so does the ego.  Experience depends on a vessel to experience with; no vessel, no experience.

So some say there is a vessel within a vessel that is released upon death, they call this the soul.  Of course there is no evidence of such a thing empirically but I suppose one could make any sort of logical argumentation that a soul is potentially existing.  Some take it on the authority of holy documentation that there is a soul, but I don't think this is any such way to get closer to the truth.  Some feel better knowing they will continue on after death, and take it an offense that one such as myself argues against its existence, but what can you do about that.

And then there are those who think this is all a simulation, and perhaps on death you are awakened from the simulation much like in The Matrix, but again, without empirical evidence of such a thing existing, only logical reasoning, it's not something anyone can really say for sure.

IMO you shouldn't waste life thinking you'll be going somewhere after death; the most certain thing is that you get one life and one chance to do something with it, so don't waste it writing long posts of forums contemplating the potentials of posthumous living.