Modeling is a way to combine play, mapping, and visualization. Many of us built models when we were kids. Looking back, it was a great way to learn the parts of a car. My brother even had a model of a V8 engine with all the pistons, pulleys, camshaft etc. I still visualize that model when it comes to problems with my 4 cylinder turbo-charged engine in my VW.
Consider how modeling might help you solve your problem. A model might be a physical model, a computer simulation (everything from weather-prediction models using supercomputers to a simple Excel spreadsheet), or maybe a diagram sketched out on a napkin. Once you have a model, feel free to play with it, make changes and see what happens. Remember it's only a model and there will be aspects of the real situation that they don't model, nevertheless, a model is a great way to develop some intuition about your situation.
Excel is a great way to build a simple model of many systems. Take some time to get familiar with Excel and move beyond simple formulas and formatting. If you're using Excel to make pretty tables or just keep lists, you're missing a lot. There are a lot of resources on the internet for Excel. Two of my favorites for picking up tips and new techniques that I can use are Pointy-Haired Dilbert and Peltier Technical Services. One of them had a great method for randomizing a list which I now use routinely to run my analysis samples in random order to avoid time effects in my analysis.