Download and install a free copy of Blender, a 3D modelling tool. (We also have a couple of laptops available at Creative Digital sessions at the Mitchell with a slighter older version on them).
Try these video tutorials that introduce Blender tools and features and finish up with a realistic-looking (but unfortunately
not realistic-tasting) donut.
Alternatively, for a tool you can use online, sign up for a free TinkerCAD account. There are some basic tutorials there under the menu "Learn" at the top of the page.
TinkerCAD Hour of Code tutorial on making an icicle
TinkerCAD Hour of Code tutorial on making a Bursting Star
