Quercus....there's a lot of territory between those options, lol. The amount of prep required depends upon the condition of your native soil, of course.

I do recommend that beginners have a professional soil test done so that you know what you soil may or may not need in the form of nutritional amendments ot pH adjustments.

I don't know where you are reading about all of the digging, cardboard, and waiting stuff......

I have well drained red clay soils that do a fabulous job of supporting plants of all kinds with very little effort on my part. I did till compost and wood chips into my veggie garden area one time when we broke ground for the first time. I maintain a two to three inch layer of mulch, applied after the seeds germinate and the plants are up. The earthworms have done all of the tilling since that one time. I direct sow everything in my vegetable garden except for tomatoes and peppers.

So, in other words, option one works fabulously for me! I fertilize, of course, but conservatively and thoughtfully.

Google double digging. That technique incorporates the sod into the bed and you don't lose nutrients by stripping the sod and carting it off. Thorough preparation is absolutely worth the effort.