ok well the shift star is on the same side as the clutch, follow your shift fork (the shifter hooks to it) and it will be hooked to the shift star, make sure it sits even the (shift shaft) and that the hooks at the end of the shift shaft are sitting centerd so it is not being pulled up or down. check to see that the return spring is still hooked to the shaft it will be where the shaft comes through.
as far as the shift forks and shift cam well there inside the motor it's self, if the cam is worn down it will make shifting hard, also the forks might be bent causing a hard shift.
go to (ALBA Action Sports - Honda, Yamaha, Suzuki Kawasaki, Polaris, Can Am, Sea Doo Parts, Accessories, Riding Gear and More) and go to the OEM PART FINDER if u want to look inside the motor to get a better understanding.