G.Depardieu is Jean Reno's 二货朋友 in Tais-toi. Joey Tribbiani is the 二货朋友 in Friends. As Stan mentioned above, 二货 is an affectionate way to refer to a friend that may not be a genius but everyone loves him. 二: stupid. 货: buddy/man/stuff. More usage: 吃货 is one that admires good food(in a less graceful way). A refined 吃货 is a 美食家(gourmet).
女人如衣服 means "women are like clothes". It's usually used with another sentence, 兄弟如手足, which means "brothers are like limbs". If you ruined your garments, you can always buy new ones. But a lost limb is a pain that lasts. And here brothers mean true friends. But this joke is just using 女人如衣服 in its literal meaning.
姐也是你穿不起的牌子！Here 姐 is just a way to call oneself. To further the comparison 女人如衣服, she says that I'm a brand that you can't afford.
再贵的牌子，试穿也是不要钱的！ I'm afraid there're a lot to cover if you want to make sens of this, so I will just write down the translation: No matter how expensive clothes are, it's always free to try them on!
This is supposed to be a joke, but frankly I didn't get it.