I want to create an application to allow me to catalog my tools and equipment I have dispatched to different job sites. I'd like to be able to search in this database, update entries, and allow me to attach links to manuals, etc.. that I have stored on my computer.
I've used VBA in the passed. I've dabbled in ArcSDE and basic touched on HTML, etc.. I'm not completely computer illiterate but I feel like I don't know where to start, or even what language to look into.
Not really so much a language as a program: namely a database.
The first thing you'd need to do is set up a basic database that lists every bit of gear you have. From there you would be able to devise a system to mark this or that bit of equipment as being "in use" and run searches for what is and isn't in use. Along with plenty of other things depending on how complicated you wanted to make it.
MS Access or the Base program in LibreOffice are good what you might call database prototyping programs, but they'll probably be good enough for your basic needs for some time. So, I would start by picking up a little basic database theory and then applying that to one of those programs.