Soot from candles can be removed by purchasing a “dry” or “soot” sponge from a janitorial supply store. They are pretreated with a chemical to remove smoke and soot and you just wipe. You don’t get the sponge wet, just use it as you get it from the store. If you have soot on your ceiling use the same technique as cleaning the wall.
If your ceiling is textured then it my not be as easy to wipe. For the ceiling you may have to buy a paint which will seal the soot, the same kind of paint you would use to paint over graffiti(can be bought in a spray can) and spray to cover the soot. Then you will have to buy a textured ceiling patch (which is also available in a spray can). Follow the instruction on the can, best of all it is not difficult and your ceiling will look as good as new.