I would urge you to try again. For amateur woodworkers, it is an incredibly useful tool; it is the same for pros but would also be money in the bank.
It may be that you were trying to bite off too much at once. If you haven't alteady done so, watch the four "getting started" videos...
Basically, one can draw anything with straight and curved lines. In woodworking, the straight ones are the more dominant and Sketchup has two tools for that: the "line tool" and the "rectangle tool". One suggestion I have for you involves scale: forget about it; it is important if you are drawing by hand but with Sketchup it has no bearing; what IS important is dimensions which are displayed in the lower right and which are pertinent to the current operation.
For example, suppose you want to draw a line that is 16 7/8" long; as you move the cursor, the length drawn will be displayed at the lower right. When I first started using Sketchup I saw the dimension box and tried to click on it so I could enter what I wanted. Doesn't work...one just starts to draw, then types the length desired (without clicking on the box) and the line auromatically shoots out. Same with rectangles except one enters the length and width with a comma inbetween (16 7/8,22 1/4 eg, fractions or decimals, either or both). Same with many other operations.
For depth/height, use the push/pull tool on a two dimensional object
Leon has mentioned the necessity of components. He is 100% right. I had many frustrations before I capitulated to his advice. After selecting an object (spacebar = select) the letter "G" will open a make component box. Why do you want components? 1. As Leon said, they don't stick to other things 2. You can use it again without redrawing (in same or different drawing) 3. #2 Saves memory and speeds operation. For example, if you were drawing a face frame, you could draw one stile and one rail then copy them for the rest of the FF.
You could do the same for a ladder...one stringer, one rung, copy. You could also draw one stringer, one rung, copy stringer then copy the one rung making ALL all rungs at any interval in one shot (linear array).
Many of the program's features won't be readily apparent, takes using it to discover them One can also Google for a "how to"; eg, "sketchup how to do linear array".
Try it again, Mike...watch the videos, play with it, Google questions or ask here.