How do I create a two-level building, for example, with steps between levels? Also, I haven't seen the bridges, pathways, and other such items in the WorldEd for doing outside things. Where are those? Thanks.
A 2 level building is not in fact a 2 level building on the map. You just build 2 rooms which are the appropriate size (they can be on separate maps if you want). Then put in a set of stairs. Put a jump tile on the stairs. When the character steps on the stairs on "floor 1" they are transported to the stairs on "floor 2" and vice versa. I advise that you undat arcanum and study the maps in WorldEd. This will show you how most things are done. The other things you are looking for are facades. Environment tab / Letter F. There is a helpful facade list which can be found in the download section.
You take an object, de-activate the "click-through" flag, and then attach a teleport script to it's "use" script point. If you need more explanation, read the AMTUT tutorial. It helps with a great many of the basics.
Scripts can be used for teleporting as mentioned but more often it is easier to use jump points. These are tiles you put on the ground e.g. on the stairs. When a player steps on them they transport him to the specified co-ordinates. Edit / jmp. I also strongly advise that you read AMTUT and then read the WorldEd manual. *All of it*. http://www.troikagames.com/downloads/worldedmanual.zip