Honestly, there's a good chance while exploring anywhere that you're going to die (I always die every time I leave home it seems). If you want to find "safe" places to check out, find a friendly old timer and ask them to show you around (or where you think you should explore). Ethereal form will save you from quite a bit, but the more I explore, the more scary things I find that can shift into the safe plane of existence!
As far as your body goes: NPCs can't destroy things. A few things could have happened: the NPC picked up your body and wandered away with it (not gone, just being held, but on a firefox, that makes it very hard to get back); a PC came upon it, took what they wanted of your things, destroyed the rest and the body; a friendly PC came across your body and decided to kindly bury it for you so no one would steal anything out of it; the "realms shifted" (reboot/crash) before you got back to your body (although I read elsewhere that player bodies are saved for a certain amount of time after a planned reboot); or you were looking in the wrong room for your body. Whether or not your body is still about can be solved by asking a friendly caster to locate your corpse.
My suggestion would be to start with priests when looking for help. They have a lot of connections, and if they can't help you, they'll probably know who can.