As I don't know your face shape, I din't what kind of frames will suit your face. Since you have a big nose, I think a frame with a low nose bridge will suit you best, which would make your nose look smaller.According to your tan skin, a black frame will suit your skin color best.
Actually, the type of sunglasses you should get with really depend on your face shape. Try on all the frames in your local shop to find the most suitable shape for you. For your tan skin, you may choose black or golden/ silver frames. For your big nose, I recommend you to pick a frame with a low nose bridge (at least not at the same height as the top bar). A low nose bridge will let your nose look smaller, while a high nose bridge will let it look even bigger. Ray-Ban, Oakley, Prada, Gucci, D&G, and etcetera are some of the famous designer glasses in recent days.