There are several ways to get a model to print
Thingiverse is a fantastic place to get free open source models.
Tinkercad is a tool we use in our programs as an introduction to 3D modeling. Tinkercad also has an online library of models you can pick from.
Fusion 360 is a far more powerful tool for 3D modeling, though it has a steeper learning curve.
To prepare a model for 3D printing, you need a tool called a slicer. Slicers take your model, and split them into layers (slices) of instructions.
You have several tools to manipulate your model on the screen, including rotate, scale, and mirror.
Step 1: Load your model.
This can by dragging it onto the build area, pressing the load button on the screen, or going to file --> Load Model File...
Once your model is loaded feel free to manipulate it how you want before step 2.
Step 2: Adding supports or rafts.
Some models will require supports or a raft to help them print. Anything with large overhangs, or a small bottom surface area can benefit from these features.
To add supports look on the left side of the screen under the supports title.
To add support material, pick if you want supports everywhere, or only coming off the build plate.
Step 3: Prepare the printer.
To prepare the printer, first check the tape on the bed. If the tape is worn out or ripped, replace it with new tape.
Also check the filament roll to see if you have enough for your print.
Step 4: Send your file to a printer.
We use octoprint as our print utility. All of our printers have an IP address on them. Simply enter that IP address into your browser to open the utility and upload your file.
Step 5: Print!!!