I'm no expert, and believe in God or afterlives sometimes but not exclusively. Most after death theories are that the body dies the soul lives on.
In my experience is a time when I passed out once, I remember feeling like a was awake but was looking into a swirling mass of colours, getting closer and closer until I woke up. What was this?
But then when ive had operations under general anesthesia, they put me under, I count to ten, once I reach four I remember nothing until I wake up, there is no dreaming, no conciousness at all. Now, had I died on the table I dont think I would even know about it, I would just never wake up.
In truth we probably will not know until we die. There may be those that have died and have stories of what happen that seem crazy, of scary.
May as well enjoy life as much as you can, deaths gunna happen to us all, so instead of worrying about it, focus on life, have fun, do scary things, be a nice person, help, laugh, dance, travel, work hard, love. Xx