Is it possible to fly by my own??

Possible, yes, recomended or likely NO! Go to a club and use an instructor they are often free and will save you a lot of money and frustration.

how long must a runway be in order for a take off?

The runway depends on the airplane. I have birds that use 3 feet to 200 feet. The problem is usualy over flight. You don't want to fly over people and that takes a lot of space.

Is this plane good for beginners?

NO, NO, NO! Use a trainer This is much more like it. http://www2.towerhobbies.com/cgi-bin...I=LXK967**&P=0 The twin you linked to is more like a third or fourth plane

In short go to a club and talk to someone. Most clubs will love to help.