What Happened?

Heh Im a newbie to GW, I made a ranger/monk and was at level 3.. I went to the city where you start then at the top it said "missions start in 59..58..etc", I didnt know what this was, then I was in the academy, and I was in red, not blue? Then I got owned by these blue comps, warrior, mage and healer... I died, then nothing happened, so I closed down GW, opened it again and the 3 ppl who had killed me were on in my party, and I had to go and kill somebody for the prince and sir tyras... Its confusing :S then I got a loading screen for Old Ascalon and decided to quit and ask this... So what happened?

You should have read the text before you clicked "Yes, I'm ready to leave it all behind".

You entered the Arena, fought 2 actual players and 2 henchman, and were then tasked with working with this team to kill a boss mob at the end of a small zone. Once that was complete you would have watched a cutscene and been transported 2 years in the future, in "post-searing" Ascalon.

Now that I've managd to travel to the future Ascalon; Is there any way to time travle back?

No, there is no going back

You can always delete that character and start over again- just be careful when talking to Tydus and don't tell him that you're ready to enter the academy until after you've finished doing everything you want to in pre-searing.

the academy is a one way trip.