I've been doing 2D CAD for about 25 years, but 3D for only a year since I bought my CR-10S. From a 2D background the leap to extruding a 2D object in to 3D space is fairly simple, but Fusion is very different to AutoCAD despite both being made by Autodesk. I did
my first 3D object in Tinkercad too but quickly found its limits and moved on to Fusion360.
Check out a chap called Lars Christiansen on Youtube - he has some great tutorials which is how I got started
I'll upload these STLs on to my web server and pm you the links shortly
