I have a phantom 2 w/ gimbal Zenmuse H3-3D. Also have a gopro hero 3+. I just got an upgraded controller 2.4ghz.On side of box it lists what is in/connected, it says Naza-M, TX, (whatever that is)  Now question is: How do I connect all this to my 7" tablet, and my gopro camera without crashing? I talked to one dealer of DJI items and he said phantom would crash because of wifi signals, assuming from camera. I am so confused, can't get any useful help.

Essentially, the dealer is correct.  The Phantom uses a 2.4 GHz frequency for the remote control.  The GoPro also uses that frequency range so there is a  possibility of interference between the two.  

The short answer is you will need a separate video transmitter operating in the 5.8 GHz range (there are other systems operating in other frequencies but this is one of the most common)  There is plenty on information here on the forum as well as other website.  But please, how about you doing some homework first?  Start with learning about FPV (First Person View) systems and then come back with some more specific questions.