Hi there Nancy and welcome
You can download the driver for the printer to install it again on your computer. this is the same file as is on the disk and you can obtain it here
Select your operating system, download the file and run the installation with the printer connected to the computer (like you did originally).
Then to print from the iPhone, once as part of the setup process, you have added the printer to your wifi network, you download the Lexmark Mobile Printing App from the App Store on your phone and this will allow you to print from it.
If you have any problems, or would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.