/3/ - 3DCG

So I made pic related, first model ever, took me like 8 hours. I already know I suck, that's not the problem; I feed the thing into Cura and it gives me a plain disk, wtf? So I try a more basic test: new project, add a cylinder, shift-click a smaller cylinder out of the middle, got a shitty donut, file>export to .stl, import into Cura... another fucking disk, and I don't know enough to know what to Google to figure it out. I'm assuming it's a problem with Cura's importation process, but this is my first time using that too, just unpacked the new printer today. Please someone help me, I'm a dumbass that already told my daughter I was going to make her some pokemon HP counters.