You give up too easy. I did a search on the truck page...
http://mtm2.com/~trucks/trucks.cgi?s=gravedigger20
... and see you haven't made any trucks yet. So why are you beginning with Binedit? That's like trying to fly when you haven't learned to crawl yet. I'd like to recommend that you begin in the same places that everybody else does. That is, start with a repaint. You can find instructions here
http://cownap.com/~mtmg/repaint/
And do a few, not just one.
Once you've got that down pat, then you can try binedit again. Runt9 has some good instructions here
http://runt9.com/mtm2tutorials/truck_ma ... torial.htm
But notice, the very first step is making sure the paths in the preferences box are correct.
This stuff isn't hard, but you can't be making mistakes right off the bat. And you can't skip steps. One step at a time or things aren't likely to go the way you want.
If you get really ambitious, then you can try your hand at some really challenging stuff.
http://mtm2.com/~d2s/mtm2tute/