You know how to script?
Well, you need to know how to script. If you want to make things like vehicles and weapons, you also need to know how to model.
Use a text editor like NotePad or NotePad++ to script. For modelling you may want to take a look at Milkshape 3D (or Blender).As for scripting, go here: http://returntoblockland.com/wiki/index.php?title=Introduction_to_Scripting
thanks, and also can you give me an idea about a m4 with a granade launcher?
Yes.It's an M4A2 Assault Rifle with a Grenade Launcher on the lower rail.