Welcome. I am working with AutoCAD for over 30 years. As you can imagine the software changed significantly since then. Fortunately, some aspects of it didn't, which makes my live a little easier.
Both AutoCAD and AutoCAD LT constantly change. I want to use it in my small business so I decided to go with the AutoCAD Revit LT Suite. It's AutoCAD LT and Revit LT in one package. It looks like learning Revit LT ma represent a small challange since there are virtualy no books about it and Youtube videos are to put it nicely, "not the best" (I find myself falling asleep, rather quickly).