A large part of using Photoshop is being able to find the graphics you are going to work with. This means organizing your photos and organizing the kits, templates, overlays and so on that you have bought. Spending time learning shortcuts to work faster will do you no good if you are wasting time searching for your files.
Organize in a way that works for you. Using a system that someone else created won't help if your brain doesn't work that way. If you think in dates, working best chronologically, a system that uses names in alphabetical order won't work for you. The one thing that will help any system is to use complete words. If you are labeling something from a trip to Orlando, "Orl" is not the best choice. "Orl" could also stand for "New Orleans" or "Oriole."
Don't think you must purchase fancy software to organize your images. I managed for many years simply using the directory structure of files, folders and sub-folders present in Windows. Now that I own the fancy software, I still use that structure as the base of the system.