Well you could do what you suggest, but you won't have a good patch of grass - in winter particularly, it will develop bald patches and go yellow in places, some will die, some will sink too low so it'll be hummocky. You need to take up the stones and concrete, dig it over and remove the weed roots, add some composted materials such as animal manures or garden compost, level and relevel, spread Growmore granules all over till its like light snow, then lay turf.

... And will the grass get enough light? is your yard one of those small ones with 6 foot + high walls? This could mean that it will be in shade most of the time.

If you don't feel up to removing all the concrete this may be one of the rare occasions when artificial grass might suit you, but the area would still need levelling first. Or could you remove the paving stones and just tidy up the concrete and plant something low growing in the soil - you would get green and maybe flowers. Hard to judge without a photo of the area.