Emulators are fine, but you should avoid sites that ask money to use them (because they are 100% fake).
Also ROMs are legal as you can by a law make one copy of your video game (if a game cannot be put on cd due to other ways, roms are a way to go). Since you usual own a part of purchase code (old games used those passwords to register your games), your copy will be unique.
Games may be made for playstation, but all games are made on PC before that .
Here is a guide of how to make your playstation games legal to use: