Chukwudi,
I encourage you to check out the webinars located at https://www.gotostage.com/channel/optiwave. I would specifically recommend the “Basic Examples & Analysis” as well as “Advanced Applications I”. These both provide a good starting point for learning to use the product.
Once you have reviewed those if you are still having issues you need to be more specific in what you are having issues with. What materials are you trying to load for example.
Scott