Mark has a good idea and one I was hoping to guide you to. It would be of great benefit to you to set up a couple of loops and a few sidings to play with for a while. This is not intended to be your final layout, just enough to allow you to loop trains and or do some switching of cars.
I did something like this for about a year before starting my current layout built. I was getting much of the same advice about loops, sidings, industries, etc. My experience with that prototype layout led me to realize that I do like occasional switching but I'm not really interested in industries at all. Switching cars showed me the many issues with couplers, weight, etc. that start impacting those operations. These can all be addressed but they aren't going to be high on my list of things to do.
