what are some tips that new players should know?

I am fairly new to chess.com and i have learned that playing the deffensive is not all ways the best idea.

At the beginner level, it's hardly ever the best idea.

opening- develop your peices with a target,
mid game - connect your rooks
End game - out play your opponent.  

You could say

opening - outplay your opponent

midgame - outplay your opponent

endgame - outplay your opponent

I'm relatively new too, what's helped me is reading Dan Heisman's novice nook site. http://danheisman.home.comcast.net/~danheisman/Articles/subject.htm

Also the videos of Roman Dzindzichashvilli where he analyzes peoples' games that have violated basic principles of chess in the opening.

Before making a move, always try to find your opponent's best reply <-- great way to avoid blunders and to understand the position from both sides.

A good place to start is to avoid hanging pieces and mate in ones. Afterwards you can start working on tactics.