When you work on a SketchUp model the file will need to be saved and downloaded as an .SKP file so that Mrs. B. can open it up in HER sketchup app and zoom, orbit, and pan around the model to see how you did! These are Step-By-Step insturctions on how to SAVE and DOWNLOAD your .SKP SketchUp Model and then attach/upload it to your Google Classroom Assignment post.
Click on this picture to go to SketchUp.com's Help Center online.
Here you'll find help with (almost anything SketchUp if you click around the instructions a bit!):
Creating and Editing SketchUp Models
Creating a Model from a Template
Setting a model's units of measurement (feet/inches vs. centimeters/metric system measurements)
Inspecting Entities (What do I know / what can I learn about each piece of geometry in the model)
SketchUp for Web Tools (app.sketchup.com)
Inserting an image of SketchUp file into your model
and more...