Right now is a bad time to do any major work as it's too late in the season. For now your best bet would be to put together a plan for next August. Also, it would be a good idea to post some photos of the lawn and figure how many square feet you have to give folks here a better idea of what you're dealing with.

That being said, having a soil test done would be a good place to start. Logan Labs is the place to go for that. With the results of a soil test there is a guy here that can tell you what needs to be done to correct the soil and give you plenty of time to get it ready for next fall. This will help to spread everything out over the next 10 months to help with the budget issue and make it less work and stress for you.

You can wipe the weeds now (and keep them under control) if you want, but it's too late in MA to reseed at this point for fall. So I'd consider a blanket spray with Weed B Gone (or a similar product tuned for whatever set of weeds you have), then spot spray things that didn't quite die.

I might be tempted to dormant seed the lawn once temperatures drop in the hopes of getting some growth in spring, but you will have to coddle that a bit over summer. It might be better to wait until late next summer (about August 10th-August 20th) to reseed.