RE: aerobird challenger (newbie here)
I would suggest that you set the Challenger aside for now and do the following:
1) Buy an AirHogs AeroAce (no substitutions) for $30 at Toys-R-Us, Target, etc. The plane is a small (9") 2-channel plane that is very easy to learn to fly, can be flown in small areas (a basketball court or indoors in a gym or barn) and is virtually indestructable. If you and your sons enjoy this plane, you can get two more (they come in three channels) and have dog fights, races, etc. Use this plane to get the feel of flying, including avoidance of trees, learning to deal with control reversal (when the plane is flying toward you left is right and right is left), respect for the wind, etc.
2) Download a free simulator program to your computer and practice flying on the simulator. Its not quite the real thihng, but its good practice.
3) When you are comfortable with the AeroAce and the simulator, go back to the Challenger or buy the Slow-V. The Slow-V is the best "real" beginner plane due to its slow flying speed. You get plenty of time to decide what control inputs to make next, but the plane is very touchy if there is any wind.
Regarding your Challenger, check that the board inside the plane has not come loose. To fly the Challenger, you need an area that is at least 600ftx600ft, clear of any obstructions. Let us know what you decide to do and what response you get from Horizon Hobby. They are one of the best manufacturers when it comes to product support. ( I should know: my son and I have seven of their planes).