There are two ways to get Isometric drawings, The first, oldest and, most difficult is to draw in Isometric view.
Type snap and then select "S" for style "enter" "I" for Isomertic "enter""enter"to end the command. This will put all of your angles in Iso view. From here you can assign hatch patterns like any other 2D plane.
The other way (the one I prefer) is to create 3D images and use the viewports in paperspace to project into an Isometric view. The standard views will do this for you
"view,3Dview,(SE,SW,NE,NW)". Instead of using hatch paterns you will use materials from the materials library, "brick,glass,and so on". to view those materials you will have to render to file, save as a raster image, then import the image into your drawing. This is for plotting purposes. If you want to view the finished process you can render view. I will caution you though if you are not familiar with 3D you may want to get a book and practice first. The reason I like using 3D over standard isometric is you only need to create one drawing for different views saving you from creating a top, front, and right side view. It also eliminates some of the mistkes that occur when creating differant views especially the iso view.