Interested in learning how to design 3-dimensional objects but don't know where to start? We recommend TinkerCAD. This is a web-browser-based software that is free to use with sign-up that enables beginning CAD designers to get their feet wet in the design process. Using TinkerCAD is extremely easy and intuitive and is a great place to start your 3D design journey.
To begin designing, head over to tinkercad.com and sign up for an account. You will automatically be directed to their first tutorial and can follow along to learn the basics. I recommend going through the first few tutorials just to familiarize yourself with the layout and the functions that are available to you. You can always exit the lesson by selecting the "exit lesson" option at the top of the page. To get to the empty workplane showed below, choose the "start a new project" option.
For this demonstration, I will show you how you can create a custom keychain using the options provided in tinkerCAD or your own artwork.
On the left side of the page are your View options. You can zoom in and out with the "+" and "-" signs and pan around the 3D plane with the D-pad. On the right side of the page you will see a sort of tool bar that contains the functions you will use to create your object. To get your base design, select a shape after clicking on the "geometric" option (image of solid cube) and drag it into the workplane. I have chosen the cylinder.
You will notice that at the top right of your workplane there is a small box titled "Inspector." This allows you to determine whether your object is a solid (and its representative color) or if it is a hole. This will come in handy later, but for now we will keep the Inspector as it is.