Someone told me that in order to make ralph jump you have to create and egg file for it.
What is the best program to use to make an egg file?
best regards
P.S. I ask noob questions cause im 12 
Blender is free program to make 3d models and animations. To export into egg file you will need Chicken exporter (you can find it here on forums). To make the texture you might need GIMP or Paint.NET or sometimes Inkscape (these are also free programs).
You have to know Python programming language to use Panda.
Egg files can hold two things: A model, an animation or both (technically they can have more information than that but this simplifies matters). Egg files start from a 3d modelling and animation package like Maya or Blender. You create your meshes and animations in these software and then export them to the Egg format for Panda to use.
If you are serious about 3d games you would want to learn one of these software. Both are well supported in Panda. Maya is commercial software while Blender is opensource. Since you are starting I recommend using Blender, then you won’t have too much problems with trying to rewire your brain to do 3d the Blender way.
To answer your question, creating a new animation for Ralph gets a little sticky as you do not have the source file for Ralph. The multiple Ralph egg files consist of a 3D mesh bound to the skeleton and other files containing just the animated skeleton. To successfully add another animation your animation must use the exact same skeleton which gets a bit iffy when converting from egg to maya/blender and back to egg.
Now, another solution to your problem would not involve creating an animation just for the jump. In the game you can move the ralph model/actor around in the Z-axis via code to make the model jump. This forum post details how to achieve this.