Your lawn may require just a simple aeration followed by over seeding and a starter fertilizer.
If your lawn is more weeds then desirable grass you may want to consider two applications of round-up. Which is a non selective herbicide, meaning it will kill any foliage you spray. Then proceed with aeration, over-seeding, and starter fertilizer. The applications of Round-Up can be applied about two weeks apart. One application may be sufficient but two will ensure the weeds definitely under control. Note: You will still be contending with weeds while your lawn in being re-established. However, with it being late in the year it won’t be nearly as bad to manage as it would be in the Spring. Once Spring arrives and your lawn is getting established you can treat the weeds accordingly.
Also: Do Not use any type of pre-emergent while the grass seed is germinating.
Basic lawn reestablishment:
Core aeration with broadcast spreading grass seed
OR, Slice seeding. Similar as mentioned above minus the aeration (aeration would be beneficial) and minus spreading the seed as for the machine will drop the seed.
The hot weather may have compromised your lawn this year. Best time to work on getting your lawn back in shape is in the fall. Trying to establish seed or sod during the summer months is not advised. Mid September first of October when the weather starts to cool down would be the correct time. Providing you lawn is not a complete lose, a good aeration followed by broadcast spreading grass seed should re-establish your lawn. Figure about 5 pounds per 1000 sq. ft.. Instead of using your late summer early fall blend fertilizer apply a starter fertilizer. Keep it watered if no rain. Within a few weeks you should have a decent crop of grass growing up from where the lawn was aerated/plugged. Make sure you have sharp mower blade(s) before cutting. Usually the new grass is robust enough to handle a frost after being mowed twice.
Usually during this time you will be contending with some weeds. You can spray the weeds prior to any renovation to get them under control. Your going to deal with weeds regardless, but you can still try to get a handle on them. DO NOT use any pre emergent granular systemic products, as it will kill new grass seed. Use a contact herbicde, as in spray only. Once your grass is established, usually come next spring you can tackle the weed issue.
The only weed I would be concerned with is Dallisgrass. A tenacious weed with no current herbicide to control it. It’s an EPA thing. A new product should be out hopefully in a year or two. The only way to control Dallisgrass would be to physically remove it after a good soaking rain. Dallisgrass look a lot like crab grass. However, crab grass can be controlled with a product like “drive 75”