Yes, Blender is not a CAD program, and is also not primarily made for drawing architecture. This means you can use it to draw very accurate buildings, but you cannot do that the same way as you draw in other programs. You have not many 2D tools, for example. If you want to draw a rectangle, you must use a plane. if you want to draw a curved wall, you should use the mesh circle and not the bezier tool. You will have a "faceted" circle, but that's how blender works. But you can lower the "facet" size (more subdivisions), so you won't see the facets anymore.
Have a look at the tutorials on the http://wiki.blender.org
page, you'll see quite quickly how things work and what is available to you. I think all you need is spend some time with blender to get used to its particular way of doing things.
But don't hesitate to ask me if you have specific questions!