Should have a VIN plate near the front forks or near the engine. if it dosnt there is a good chance it is stolen. The VIN plate will tell you all you need to know.
...the model and year though? I know the bike is a yamaha 100cc cause it says so on the side sticker in larger numbers but it has no letters in front of it. The bike is fairly new but definately not vintage. probably 90's.