CME?

What exactly is Coronal Mass Ejection? Does it imply that our sun is going to die soon?

Sun will not die due to such solar activity.

The actual mass lost due to a CME is minuscule compared to the total mass of the sun. Apart from CMEs the sun also continuously loses mass in the form of the solar wind. The total mass loss rate is around in the order of 10^-10 solar mass per year. The sun will exhaust its nuclear fuel in another 5 billion years. In that time it cant loose all its mass in this way. So, yes, the sun will die. But it will die when it burns up all its fuel. It will not die by mass loss.