I don't think your radio is the cause of it not starting and not going into gear. Being hard to start is usually caused by a low battery in the igniter, bad glow plug, or poorly set needle mixture. Charge all batteries, try a new glow plug and return needles to factory settings (see manual for factory settings)
As for the radio, reading the manual is your best option.
Not going into gear could be caused by
clutch problem
stripped gear, spur gear, tranny gear
bad one way bearing in the two speed gears
Just because it's new doesn't mean you can't break it. It's only a week old, call the hobby shop that you bought it from or Horizon hobbies and they should take care of it for you.