Welcome Cook4u! We're all familiar with those rocks you're talking about but I don't know if anyone here has tried using a rake attachment on a tractor. I hope someone will have some experience to share.
Are you planning to rent or buy a rake? You may want to call around and see what's available to rent and then look for reviews on that type of rake on the web before you do anything. Some may work fine for smallish rocks but I bet you have a few bowling ball size or larger rocks in the mix if your yard is like mine. There is one called a rock hound that puts them into a bucket for you but it's for small (under 6 inches I think) rocks.
Are you planning to rake them to the side and then put a scoop on the tractor to move them?
I plant veggies around my yard but don't have a real garden. I'm interested in what you decide to do. Please report back.
Best of luck with your new garden.

I have a rock fork that was a gift. But if the darned thing is full of rocks with the dirt sifted out, I can't lift it!

I have never used a rock rake on the tractors. I just hand rake them off my various plots. But I am not as rocky here as some.