CommandoScout10
First time out of the vault

I followed the directions in this video, but when I tried to test it out I just spawned in arroyo. I have also provided a screenshot for reference.
[Area 01] ; The Den
area_name=Den
world_pos=473,272 ;573,222
start_state=On
size=Large
townmap_art_idx=160
townmap_label_art_idx=372
entrance_0=On,124,293,Den Business 1,-1,-1,0
entrance_1=Off,256,334,Den Business 2,-1,-1,0
entrance_2=Off,-1,-1,Den Residential 1,-1,-1,0
Your Youtube link is broken (at least for me), are you referring to QuantumApprentice's video?
You say you spawn in Arroyo when you try to test it out, do you mean spawning as in when you start a new game? If you're trying to edit ddraw.ini to make your custom map the starting map, perhaps you forgot to take out the semicolon at the start of the line? eg ;StartingMap=MyMap.map.
Did you add entrance lines to the entry in CITY.TXT? For example, here is The Den. The entrance lines refer to the different areas you click on when you enter the map. The names in these lines (eg Den Business) refer to entries in MAPS.TXT which you need to add.
Code:[Area 01] ; The Den area_name=Den world_pos=473,272 ;573,222 start_state=On size=Large townmap_art_idx=160 townmap_label_art_idx=372 entrance_0=On,124,293,Den Business 1,-1,-1,0 entrance_1=Off,256,334,Den Business 2,-1,-1,0 entrance_2=Off,-1,-1,Den Residential 1,-1,-1,0