Agriculture -What is this and how do I get rid of it
We cannot make an accurate identification based on your photos and the grasses have been cut and mown.
We think this may be a mixture of grasses of different species but cannot tell which ones they are. If you have some bare spots, it is a good idea to seed and thicken up your turf. Fall is a good time for seeding and fertilization.
If you have not had your soil tested in the last several years, results give pH and nutrient deficiences. https://extension.umd.edu/hgic/topics/soil-testing
Here is our list of tall fescue cultivars, seeding, and fertilization recommendations https://extension.umd.edu/hgic/topics/soil-testing