This applies to Accords 1990-2007 with auto tranny ( of course )
the brake switch is one of the things that could cause this issue .

This diagnose also applies if the brake lites do not work ..

If you cannot get the car out of park, toot the horn, if the horn works the fuse is ok,, Also if the horn works chk to see if the brake lites work, have someone step on the brake while you chk to see if brake lites work.( we will come back to this later ) ..

If the horn does not work, first thing we need to do is to chk the fuse ( the horn and the brake switch share the same fuse )
the fuse is located in the underhood fuse box for all the year accords

1990-1993 ... fuse # 25 20 amps
1994-1997 ... fuse # 30, 20 amps
1998-2002 ... fuse # 47 , 20 amps
2003-2007... fuse # 13 , 20 amps.
If fuse is no good replace it and see if your issue is solved...

If horns works, fuse is good and brake lites do not work .

You need to chk the brake switch status, switch is located under the dash, at top side of brake pedal ,,unplug the connector , use a paper clip and jump 2 wires together ( color later) ..This will bypass the brake switch and if you can get it out of park now, the switch is at fault ..

the wires you need to jump at brake switch connector, ( connector unplugged of course)

1990-1997 jump the white/yellow to green white
1998-2002 jump the white/yellow to white/black
2003-2007 jump the red to white/black .

Again if after jumping these wires together your issue is solved, replace the brake switch ..