You should NOT disk before plowing. Plows work far better with firm soil than soft.
How can we teach you how to be a farmer in thread.....
Trial and error. If you are using raised beds or plan to plant on a ridge, that cultivator will be of no use. I'm not sure why you would need to go ridge plant and raised beds in a garden. If the area you want to garden is low.... haul dirt in and raise the area.