The best method of controlling unwanted plant growth in that large am area is to till the soil and then, once the soil has been amended, lay sod which though more expensive would provide a quicker cover then seeding would. Covering the area with either newspaper or plastic (not a good idea) will take several weeks to work taking the yard out of use for the whole time.

While tilling gives the appearance of controlling "weeds" it can (and does) bring up more "weed" seeds that have been buried that then can germinate and grow, often resulting in an even "weedier" garden. Mulching is the best, and most consistent, method of "weed" control.

You could rake the area to pull out the now dead unwanted plant material, loosen the soil a bit and in a couple of weeks toss some grass seed there and spend the next several years fighting to keep the grass growing and the "weds" under control. or you could take the time now to properly prepare that soil. A good reliable soil test, Colorado State University does this for $35.00, is a good start and will let you know what needs to be done to begin getting that soil into a good healthy condition to grow grass. These simple soil tests, 1) Soil test for organic material. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. 2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains’ too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up. 3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart. 4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell, to a point. Too much organic matter can be bad as well. 5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy. may also help. Your Colorado State University people will also have some good information about growing a good healthy stand of turf grass. kimmq is kimmsr

Preen has always worked out great for me in controlling weeds. It will not hurt full sized plants and will stop weed seeds from germinating. See https://theherbladyblog.wordpress.com/2017/04/01/how-i-control-weeds-in-my-stone-pathways/