You are far more likely to be seen if you are wearing bright colors with fluorescent or reflective markings than all black. Bright colours work best and some have reflective and fluorescent properties which make them easier to see at night. Avoid black and white if possible. If you must wear all black, a high vis reflective vest or Sam Brown (belt and brace), will improve your safety, as will riding with your headlights on.
Nature protects your body from the everyday knocks and abrasions, by covering it in a protective flexible layer, a few mm thick - called skin. Believe it or not it's actually pretty abrasion resistant.
Probably the best mammal to fall from a motorcycle is a COW - it's skin will last ten times longer than yours when sliding along a road. Hence leather is about the best abrasion resistant material for motorcycle clothing. It's also pretty good at insulating you against the heat that is generated by friction between you and the road.
If your not really into leather or you want something perhaps more waterproof, there are other materials such as Cordura or Kevlar which also have pretty good abrasion resistance.