Things I learnt:
Get a couple of really cheap bits to learn with, as well as a selection of soft and hardwoods to play with. You will break one or two bits as you do stupid cnc tricks, no reason to tempt Murphy with the expen$ive bits 
I’d suggest: 1/4" upcut endmill, 1/4" downcut endmill, 1/8" downcut endmill, a 60˚ V-bit and a surfacing bit.
If you can make Fusion play nice with CNC gCode, great! While I use it for my 3D printing, I’ve found Vectric’s vCarve to be a better fit for what I do. Step 1: set up a workflow and tool chain that lets you easily get from idea to gCode.
A sheet of MDF and a table saw make a great first spoilboard. Play with the up and downcut bits to see how they behave, get familiar with feeds and speeds, chip load and what good -vs- bad chips look like. Watch Garrett @ IDC’s beginner videos.
Make a couple of jigs (example on etsy) out of MDF as an excuse to learn by doing.
Use the machine to mill out a real base/spoilboard with dog holes or threaded inserts or T-Tracks…
Learn how to do vCarve inlays and make a sign for your shop.
My “order of purchasing” list would be: Altmill, ER20 Spindle, autoZeroTouch Plate, a couple of cheap bits, dust collector, dust boot, Tool Changer/ATC (either Sienci’s or Rapidchange, depends on your givens and druthers), good bits, … vortex can always be added later.
In other words, be methodical, master the basics, and have fun!