How can I build my own weaps?

So, is there a guide on building your own weapons? because I'm in the dark.

Well, if you want to make a weapon using the decorate system in the unofficial build of ZDoom try the following link:
http://www.zdoom.org/wiki/index.php?title=Creating_new_weapons

If you'd rather get started with EDGE (which, in my opinion, is easier to learn at first because it's better organized) then you can get started with the DDF Online reference guide and continue from there with the Doom Armory's tutorials section which contains lots of stuff from projectiles, to reloading, shell casings, bouncing projectiles, etc.

Okay, thanks alot!