Warning: Your Chromebook has limited space for storing files locally. When saving a file to the Chromebook and there is not enough room left, the Chromebook may automatically delete some of the downloaded files to create space to accommodate the newest file.
While connected to Wi-Fi, go to your Google Drive, select the page, image or document you want to save
Right click (two-finger click on the trackpad) on the file and select Download
More information: How to use your Trackpad | Chrome Help
If downloading a Google Doc, your file will be converted to a Word Doc
A confirmation box appears in the bottom right of the screen when the file has finished downloading
To access your files while offline click on the Launcher (circle in the bottom left corner) and click on Files
A new window opens, click Downloads in the left column and you will find the file you have downloaded
Changes made to the file while working offline will not automatically update the original file in your Google Drive. You will have to upload your edited file to your Google Drive once you are connected to Wi-Fi again
More information: Open, Save or Delete files | Chromebook Help