You're going to have to open up the console and figure out a few things for yourself - there is an electrical interlock, wired to the ignition switch via a switch at the top of the brake pedal, and there's the lock button on the shift lever itself.
If the interlock solenoid does not unlock when you step on the brake with the ignition on, start with the "back & turn" fuse - make sure the reverse lights & turn signals work - if that fuse is blown there is no power to the switch on the brake pedal, if that fuse is good, you'll need a meter to determine where you're losing the power to the solenoid. Be aware that the NSS (neutral safety switch) on the transmission is a part of this circuit - the shift has to be in Park for the solenoid to energize - I can supply a diagram if you need one.
If the solenoid does unlock, check the operation of the lock button on the shifter itself - I have seen at least one case where the plastic plunger at the top (inside the shift handle) broke, I replaced it with a hand carved wooden dowel.
