You won't know what's in those 5". The grass could be spreading everywhere. But the moment you see a green grass growth pop up, try to pull it.

If you know the general spot, you can also repair it with some additional paper by digging out the dirt again. Best to do it now before more planting and growth occurs.

Fives inches of soil isn't much. I would expect the grass to grow fine. How about before you put any plants in there, you put on some garden gloves, get down on your knees and grub around. You'll figure it out pretty fast. If it turns out you would be better removing the sod due to the timing of this, others undoubtedly have a favorite method they would share if you ask.

I'd hate to think you gave up on the idea of gardening because something like this set you up for failure from the start. My love of gardening has seen me through good times and bad times. Those bad times were pretty bad...and it was the garden that healed my body and soul in a way my team of doctors could not. My garden saw me though the death of my life long partner in a way my family and friends could not. And the garden keeps me active and exercising, while I see others my age not doing as well, as they spend their days in front of the TV.

Gardening can be a life love love, so getting started right is worth the effort. Plus you get tomatoes.
Good for you finding this group and asking.

Good luck. :)

That depends on which grass species you have. Putting 5 inches of anything on many grasses can kill them while some other, more invasive, grass species will only be slowed down a bit.
The United States is a pretty big and diverse place with many soil types as well as climates so a bit more information about where you are would be somewhat helpful.

Ditto what kimmsr sez - there's grass and then there's other grass. I've got some brome grass here that just thrives when I put 18" of soil over it.

how big are these beds, and is there some edge to them or was it just piled up without an enclosure? I have 4 foot squares - if it were me starting out in the season with the size of bed I have, I woud lay down a tarp next to the bed and remove the edge, and rake the soil onto the tarp. Then I would lay down a couple layers of cardboard on the area, wet it down, and rebuild the bed. So, not knowing the size and edging, etc, I am not sure this would work for you. But I would hate to pull grass rhizomes all season. For my squares I had the cardboard extend beyond the walls of the bed so that I could put wood chip paths around the squares and grass could not come up. Good luck!!

so your all saying to dig out my bed and either remove the grass or put down cardboard. Well I've planted in all my beds except 1. I put up 1 by 8 wood frames around my beds. Im not sure what type of grass i have ill take a pic and post soon. I think i answered everyones questions.

About all you can do at this point is watch for grass coming through and kill it. Snip it off and mulch with something dense like grass clippings.

If it gets really bad, this fall you can dig it up and turn everything over to kill it off.

Yes, at this point, garden on!