Should I turn the gas off when I'm not using my bike? And when I'm washing my bike can I spray directly on the engine with the hose. (it's covered in mud/dirt)
If you don't turn the gas off several bad things can happen:
1) Eventually the float valve will leak. It may leak only a tiny amount but it can still be enough to create a gas spill that could be dangerous.
2) the gas in the carburetor will partially evaporate out, basically distilling itself down to goop that won't evaporate. One bowl full will not produce enough goop to worry about, but if you leave the gas on you can distill down the entire tank into enough goop to clog the carburetor jets
Washing the engine shouldn't be any issue. If you use a pressure washer it is advised to avoid the seals around the shift shaft and suspension bearings as the extreme pressure could damage them or force water where it doesn't belong. A nozzle on a garden hose shouldn't be any problem at all.
Thanks for the help Rod I appreciate it, since I bought the bike last Saturday I havn't turned the gas off after riding, should I be worried or do anything? The bike seemed to be running good today, except it will only idle for about 5 seconds and then it will die, how can I fix this?
And yes I ordered a service manual, it's should be here within a week.
Just turn the gas off and continue to do so when its not running. Its all in the owners manual. If I were you, I would read the "Operation" and "Maintenance" chapters in that order as soon as possible.