Try talking to all people at Syd Garden. Then you will get a call from Randam. After meeting him and going to the hospital, you will be able to enter the mirror house (I hope)
Btw, here you can find the maps of the game.
I really dont know how to edit posts. But I have one last question. I got through the mirror maze and also made it through the 2 levels after the mirror maze and ran into a sealed door. What do I do now, do I go back outside to Randam?
I was able to make it to Jamie in the snatcher base. When I battle the boss after that, the boss uses lucifer b and since I dont have an anditode, I die. Where do I find the anditode?
You should go back to the submarines amongst the snathcers there is one with a yellow bottle dont'shoot the bottle. take the bottle after the kill. it is the anti-dote which will protect you in the final battle.