My car stuck on park and only engages other gears smooth?

I got a 96 maxima when i try puttin the stick on drive the button to engage is stuck on park but when i get it to my to D it engages all smooth to the rest of the gears, someone told me theres an anti lock disengage button near it but i guess this car doesnt have it i looked and nothing. can someone please whats going i appreciate it.