transmission gears wrong

can someone tell me why my stock peerless on my craftsman lt1000 has the problem of not going into reverse (on the shifter) , when i shift what should be neutral is reverse, first is neutral, and 3 4 5 6 are the same? need it fixed asap

The shift linkage may be loose or damaged. Or where the linkage bolts to the selector shaft on the transaxle may have worn into an oblong shape. I've seen that happen multiple times due to the bolt loosening up.