John,
When it comes to model railroad "operations," there is a lot of existing information out there. For starters, there is an NMRA Special Interest Group for Layout Design (LDSIG). I believe they have a Facebook page and operate under a group.io format as well. I signed up to get their e-mails from group.io (which is a Google operation, I believe) and the information they discuss can be quite useful. Their focus is on layout design for better operations.
There have also been numerous articles and authors that have discussed this topic, starting with Frank Ellison in the 1950s(?) (a 6 part series in Model Railroader called "The Art of Model Railroading") and continuing today through people like Tony Koester. There are also quite a few books on the subject, but the one most often recommended is "Planning Your Model Railroad for Realistic Operation" which is a Kalmbach publication, I believe. "Operating" a model railroad can be tons of fun if you design your plan well, but as I view it, your current plan is really only good for "looping" with the added ability of changing the trains / engines that run the loops.
To operate, you have to get down to the nitty-gritty of what industries you want to model or what locations (whether towns or areas of the country) you want to model. Some people prefer to model large industries like steel mills, coal mines, refineries, or automobile manufacturers. Others prefer to model smaller industries built within or near towns (including ports), while some prefer to model unit trains hauling their dedicated cargoes between large yards. Finally, there are those that like to model passenger operations (either city-to-city or commuters) and those that like to model short-lines that only serve a few customers from an interchange with a Class 1 railroad.
Whatever you choose, it might also help if you develop a "back story" for why your railroad exists, if it is fictional. If not fictional, use location names that at least sound like they might have been found along the railroad you model. E,g., you would probably not find Sonora along the Pennsylvania RR.
As you can see, the "operation" possibilities are quite open, and anyone wanting to help you must know your limitations and choices, something the planners call "givens and druthers." One thing I've learned from the LDSIG and other readings is the idea of LDE, Layout Design Elements. You get ideas (including from other people's layouts) from anywhere about what you like to have in your layout (a port, a steel mill, one or more small towns, an interchange, etc.), then you draft a scaled down version that meets your needs and will fit in your layout space without overpowering it. Then you try and fit as many of these LDEs as you can into your layout, connecting them all in some logical way (or any way that makes you happy, as long as it makes operating sense).
You have to be the one to choose and design your LDEs. Once those are done, friendly people here will offer suggestions for improvement and might even offer suggestions for how to squeeze them into your space in a logical manner.
Good luck,
Chuck
