Your grass looks like tall fescue, the best type for most Maryland lawns.
Reseed the dead patches in late August-early fall. Here's how to do it: https://extension.umd.edu/hgic/topics/lawn-renovation-and-overseeding
You might want to get the soil test done now, so if lime is required, you can apply that immediately and let it get started. Soil testing: https://extension.umd.edu/hgic/topics/soil-testing