How do I get Google Drive to sync?

1.Start Google Drive.

• On a Mac, go to Finder  Applications  Google Drive.
• On a PC, go to Start  Programs  Google Drive.

2.Click the Google Drive icon .

• On a Mac, the icon is usually in the menu bar at the top right of the screen.
• On a PC, the icon is usually in the taskbar at the bottom right of the screen.

1. In the top right, click More 
2. Click Preferences  Sync Options  My Drive.
3. Click to choose which folders or subfolders will sync:
   • OPTION 1: "Sync everything in My Drive."
   • OPTION 2: "Sync only these folders."
4. If you choose OPTION 2, click the box to the left of the folder names to choose what folders will sync.
5. Click Apply to confirm your changes.

Change download & upload rates

1. Click the Google Drive icon .

   • On a Mac, the icon is usually in the menu bar at the top right of the screen.

   • On a PC, the icon is usually in the taskbar at the bottom right of the screen.

2. In the top right, click More   Preferences.

3. Click Advanced  Network settings.

4. Click the button next to the"Download Rate" and "Upload Rate" option you want:

   • To use a slower rate, choose Limit to and use the arrows to change the rate. The numbers are measured in kilobytes per second.

   • To use a faster rate, choose Don't limit.

5. Click Apply.

Source : https://support.google.com/drive/answer/2375083?hl=en