If you make your models and environment is it ok to use online textures or do you have to make them yourself. 

On the page it says this:

RULE CLARIFICATION: You can use any pre-made art, code, fonts, sounds... just make sure to say that you did so in your game's credits. You'll likely get a poor rating in such categories, but only out of fairness for those who made what you didn't from scratch. :)