is it 4.5 billions years old or 35 billions years old, or is it just undecied..

Also are all the huge solor flares normal, has the sun ever acted up like this is the past

The Sun is 4.6 billion years old.

When the Sun was young, it probably spun faster, which caused it to have more magnetic activity--spots and flares--than it does today.

The universe is only 13 billion years old according to WMAP analysis. 4.5 billion is the consensus for the age of Sol.

The sun goes through cycles of solar activity. There's an 11-year cycle, and some researchers propose a longer 70-year cycle. You can find more information by looking up "solar maximum" on Google.

Here's some stuff to get you started.
http://www.spacew.com/swim/bigstorm.html

As you can see, we are currently coming off a solar maximum, which was in the spring of 2001. Did you notice the world ending in May 2001? Well, we had even more solar flares and sunspot activity back then than we are having now, and I didn't notice the world ending.

Don't listen to the folks on Godlike who try to tell you that "we're in an unusually strong period of solar flares". It isn't true. It isn't unusual at all. The sun has been having solar cycles probably ever since it began operations, and certainly since people began observing sunspots back in the 17th century or so.