Is there any risk that Google Drive will overwhelm my storage?
No. The files and folders in Drive are just links, so they take up very little room. If you were to make your entire Drive available offline it would take up more space, but in most cases that shouldn’t be enough to overwhelm your local computer’s storage.
How do I access Drive?
Your entire Google Drive contents will show up under a new drive letter (typically the G: drive).
This can be accessed from Windows Explorer (file browser) or through the white Google Drive icon 
that appears in the system tray (single click, then click on the folder icon in the pop-up window that appears).
How do I make a desktop shortcut to the G: drive?
Browse to the G: drive via Windows Explorer (Start > Computer). Right-click the G: drive and choose “Create shortcut”.
Can I access files in a Google shared drive using Drive?
Yes, when you open the G: drive you will see both My Drive and Shared drives.
Are files shared with me accessible offline within the "Shared Drive" folder?
To make a file/folder that was shared with you by someone else visible in Drive, you must "Add it to your Google Drive". Then Google will make a "synchronized copy" to your Drive and it will be shown in you the Drive application.
Can I edit and save files in a Google shared drive using Drive?
Yes, provided you have full access to the Google shared drive. Depending on what level of access you have been assigned to any shared drive, your ability to save/edit shared drive files via Drive may be limited.
Do I need to choose which folders I want to access?
No, every folder and file in your Google Drive will show up in the Drive application.The files and folders are not saved to your local computer. The cloud icon on the folder tells you that the file is located in the cloud only. Files with a silhouette indicate that they are shared.
Can I save and open files in Drive directly from programs like Microsoft Word and PowerPoint?
Yes, just open the Drive drive letter (G:) like you would for a file in My Documents or the Y: drive. Note: Drive works best in storing Office documents that only you edit. If it is a collaborative document, you should ideally use the equivalent Google Workspace Tool (Docs, Sheets, etc.)
If I save a file in the Drive G: drive does it remain on my computer?
No. Data stored in the G: drive is “streamed” on demand from the cloud to your local computer. Local caching occurs as you access and modify data, but a local copy of a file is not accessible unless you choose to make it available while offline (see below).
Is it possible to accidentally delete the whole drive?
Yes, it is. However, when you delete a file from Drive, the file will be moved into your Google Drive trash, not the trash on your computer, so you would still be able to restore them so long as you have not emptied the trash in Google Drive and it is within the 30 day restore window.
Can I make a file or folder available when I’m offline?
Yes, if you anticipate that you will not have a network connection and would like to retain access to a particular document you can make it available while offline. Right-click the file, hover over “Drive" and select “Available offline”. Note that Google Docs, Spreadsheets, etc. cannot be made available offline.
The file icon will change to a blue circle while downloading and then change to a green circle with a check mark when done.
The file is now available offline. If you modify the file while offline, the file will sync the next time you connect to the Internet.
Note: You should NOT make your entire Drive available offline. Storage on Google Drive is unlimited, while disk space on your computer is not.
Are there any important differences between running this app on PC vs. Mac?
No. The functionality and look-and-feel are virtually identical. Drive mapping is different between the Mac and PC, but that’s due to the differences in the operating system not in the Drive app.
Are there any risks to having the Drive stored on my device?
No. It is just as safe as accessing your Drive through a browser. The files and folders you see in your Drive are really just links to their online versions, so the standard protections that Google employs to safeguard your file security online is still in place. Additionally, your data is encrypted and you have versioning, to revert back to previous versions if the need arises.
Can I use Google Drive to run a backup other folders or an external hard drive connected to my computer??
Yes. There is a separate KB article on this topic titled: Google Drive: How to backup local folders