Welcome from Pittsford, NY (suburb of Rochester)!
That is beautiful 1973 Mustang Convertible! I am glad your purchase turned out to be a good one. Lynda (wife) and I have several pony cars in out corral. Our 1973 Convertible is a fan favorite. It only has a little over 20,000 original miles on it, and is in excellent preserve condition (barn stored over 40 years). We enjoy all of our pony cars, but this one is quite special. It has a 302 2v engine with a C4 automatic transmission, so it is not a fast car. It also has Power Steering, and we added air conditioning. I replaced the mechanical fan and original radiator with a three row aluminum radiator with a matching fan shroud, and dual electric fans just because I could. It is a very nice cruising machine.
If ever you have a question or need hep let us know. There are a lot of folks in this forum who are both qualified and willing to help. If you need technical manuals my Go To site is Forel Publications at:
https://www.forelpublishing.com/clickbank/index.html#1973
All of the Forel manuals are downloaded PDF files. The colorized Electrical Wiring Schematics manual is very nicely done. And in the Shop Manual, Volume 6 you will find a lot of engine emission control system information and engine vacuum schematics for a lot of engine calibrations. I found two additional schematics not included in the Volume 6 pages, and attached them to this post for you to download if you like.