We would recommend starting with a fertilization and weed control program to improve the existing health of the turf. Then we would aerate and overseed in the fall and continue the fertilization and weed control program. In some scenarios where the existing turf is in poor shape, it can be advisable to not lay pre-emergent in the spring and let crabgrass grow to provide coverage over the lawn, as opposed to preventing crabgrass from germinating and being left with bare spots for an extended period of time. This is on a case by case basis and we would advise you if that is needed in the short term. Since crabgrass is an annual weed, it will die out on its own just at the time that we would aerate and overseed. Once completing the fall aeration and overseed and the new turf is mature enough, we would be able to continue weed control and you are well on your way to having the yard you envision.