Answer: The first thing to do is run some basic soil tests to check fertility and soil pH. This will tell you how much to fertilize and if you need to add lime, as well.
This summer, mow at a height of three inches. Mow often enough that you never remove more than one third the grass height at a time. This will encourage the existing grass to grow denser and begin to crowd out weeds. You could also spot treat perennial weeds by digging them out or with an herbicide containing glyphosate. (Read and carefully ALL of the label directions, this is a nonselective herbicide and will kill grass as well as weeds.)
The best time of year to do major lawn work is late summer to early fall. Your local Rutgers county extension should be able to help you with the testing and interpreting the results, as well as help you analyze the existing lawn in terms of whether you can overseed or if you need to renovate. In the meantime, here is some lawn care information you may find helpful in planning what to do.
I should also mention that lawn grass needs full sun to grow its best, with a minimum of half a day of sun to stay healthy. If your front yard is shady, you may want to consider using a shade tolerant ground cover instead of lawn grass. You could look into groundcovers such as Vinca minor, Hedera helix, or Ajuga for instance.
Good luck with your yard this summer!
Q&A Library Searching Tips