How do I track the device (including the exact time and location) used to access my account?

Please go to Profile Settings to see those details. 

You can access a separate section called, "Privacy and security", in your Profile Settings.

If you suspect that someone gained access to your account, you can stop this activity at any time. There are 2 ways to do that:

1. Terminate a specific session by hitting Log Out on the right hand side.
2. Terminate all sessions (except for the current one) by hitting Terminate all Sessions.

Note that terminating a session on a device may result in all unsaved changes made on that device being lost.