The word "pas" has different meanings. It can be "a step", "the doorfront" = le pas de la porte or it can be used in negation with "ne pas" = not to. Exemple: Ne fais pas ça! = Don't do this!
"Rien" is pronounced with a sound that doesn't exist in spanish, you can listen to this song to know: http://www.youtube.com/watch?v=ThYh4dBaEls
As for the structure of sentences, could you give any exemple in english to translate? You want to know the order of words right? Basically it's Verb+ Noun + Adjectiv