Orchids from seed is a complex and long process and usually done in a lab. Unless you want to wait 10 years for the result try it with a Phalaenopsis and not a Catleya.
First you need to do the cross. Pollination is usually done with a toothpick. If you are selfing then Use the toothpick at the right time and lift the pollen and place it on the sticky part just behind it. If you did it right the flower will go to sleep the next day, so will the rest of the spray. Make sure you label the tag with the plant's name x self and the date.
The ovary will swell and a few months later the pod will be ripe.
In the meantime look for an orchid club and see if anyone has a lab. Some orchidist do their own crosses. An active lab will probably not let you in since everything in the lab needs to be very clean. They can show you the process.
This video was well annotated but this is not the set up I know. The video I found had no sound but it showed how the orchid pod is sterilized.
Most people now don't do their own flasking anymore. It is cheaper to send the pod to Thailand and have them do it. Orders are usually about 10,000-50,000. Realize an orchid from a seed is a crap shoot, 99% won't be award winners. If you want a predictable plant then clone it instead.
Happy gardening in Hawaii. Gardens are where people grow.