A layman's question about Thermodynamics (End of the universe)

I am little experience of physics so please be patience with me, This is my first post of this great internet forum.

I have a friend who said that energy will never remove from the universe only transform (e.g. cogs loses energy from friction that´s turn into radiation).

But if that true how come the universe will end? What´s the name of the theory about the end of the universe?

if energy is constant universe wouldn't universe live forever?

thanks for your time best regards Conny. :)