Hello, Shiela,
I hope I can help you with some guidelines. In your post you said that the CDROM light is off and it does not read data.Did you recently inatall any program or hardware ? If so unnistall it. Please, make sure that it is recognized by the BIOS, so check the setup program and make sure that it shows the CD there. Also make sure it shows under device manager (if you are using Windows) and there is not a conflict or missing drivers ( a yellow or red mark ). If the CD is installed correctly on the software side, them it is time to check if it is receiving power from the power supply.
At the back of the CDROM there is a ribbon cable, usually used for data, a power connector and a sound card wire. Please understand that if you are not so confortable to work inside the case, do not do it, there is a big chance of damage to the internal parts and to you in there. Please use an electrostatic protection kit and unplug the Pc from the receptcle, then open the case. at the back of the CDROM you will find those cables, make sure that they are tightly conected ( do not force them into the CDROM to not break the circuit board inside it). If your floppy drive is working, remove its power connector and insert it on the CDROM. Close the case and boot the Pc ( you may receive an error message from the Pc, just ignore it). If now it works, the problem is the power connector from the power supply - inspect it ( look for a burn wire or anything strange ). Please post results and if you need more help.
Mac.