firstly i dont know much about programming the arduino.
Then an 18 joint robot is far too ambitious a project.
so i was wondering if there was software that writes the code for you
The soft stuff between your ears...
or code available that i can copy and past into the aduino that runs with the mega shield.
Probably. If your legs are exactly the same as someone else's, and are positioned in exactly the same places.
secondaly how easy is it to control all this from my android phone?
Use the phone to press the ON switch. That was easy. If you meant something else, use terms that have specific meaning. "control" does not.
Also once i can get that far I will want to add some sensors so it wont bump into things or walk off of tables and stuff, maybe even go up steps but i feel this is getting ahead of myself at this point
That I can agree with.