I wear bike shorts that fit properly. Some find they like bibs better. It depends on your build really thin guys and guys with big guts are both likely to gave a hard time keeping regular shorts up, but there are probably other factors. Figure out what works for you, but they need to fit.

Jerseys are nice. I have worn them on most of my tours, but have started using a little backpack and wearing tech tees instead lately on some tours.