Welcome to the Forum! Congrats! You've got yourself a project! IIRC you mentioned in your other thread that you're 16, this project will be a handful for you and keep you very busy, but can teach you a ton about cars

An attempted word of wisdom from someone who has been where you are many, many moons ago...patience and focus!
Many youg fellas might get ahold of car like this and want to gut it to the frame, drop a bent8 in, re-do the suspension, re-do the interior, etc, etc and mainly...they want to do it all at once

Problem is in a 'tiger by the tail' approach like that you'll quickly find yourself overwhelmed with the amount of work needed, and possibly find little satisfaction, cause it can be difficult to complete a dozen projects all at once, and lacking completion of any single one will wear you down...seen it happen too many times. So please don't take offense to that short sermon, really intended as friendly words of advice.
As another venerated member of the forum mentioned in your other thread...start with what do you "want or need" to get out of this car...occasional race car...daily driver...somewhere in between?
IIWIYS, I'd pick one area/aspect/project to work on first that will yield some accomplishment=satisfaction=reward. So for arguments sake let's call 'Project 1:gettting running'...now within each bigger goal are smaller projects that will require their own focus, patience and above all knowledge and research
So 'part A of Project 1 is getting the carb functional' (maybe it should be a battery and checking if she'll turn over, but again for arguments sake let's use this as an example):
For example getting her running Part A...I'm gonna guess it's not been run regular, has it? In that vein, your carb looks like a holley 1940 service replacement (I am not positive) with some type of adapter on the base I am not familiar with. In order to get the linkage hooked up and operating you should research that carb, take some more pics of it closer up from all four angles, and first decide if it is a carb you will stick with, given the immediate goal (Project 1 Part A) or switch carbs. If sticking with it, then the first thing to do is likely a rebuild.
So you have to learn about rebuilding carbs, getting the right kit, the linkage, it's compatability with the current ignition system, etc, etc, etc.
Point of all this is not to give you a brush off by any means, but to suggest you approach something of this scope "pragmatically" which is where more patience and focus come into play...but saying that, you really need to narrow your focus...and no offense intended here...but to post 27 pictures and ask for 27 answers (correlated back to your pictures) is a bit too much to ask. There are plenty of people more than willing to help on this forum, and more than I'll think you'll find on many other forums, but it's still best to govern your approach...again just friendly advice
I or someone else could sit here and rattle off, 'the door under the glove box is a fresh air door, the duct tape looks like it's holding the heater plenum together, it looks like a 200 not a 250, the weather stripping on the window pictured is shot and the chrome trim is missing (window will have to be pulled and replaced), the pvc hose is not connected and should be reconnected (black hose going to nowhere pointing toward radiator with clamp on it), if water is leaking inside car then heater core or connections are shot, if leaking at radiator then radiator likely shot.......and this could go on, and on and on
Point of all of this is, you'll get the most hope, and the most help, and the most out of this if you slow down a bit and narrow you objective down considerably

Again, not to give you the brush off cause I wouldn't take the time to type all this if personally I wasn't willing to help....but as in any situation help is most worthwhile for those willing to help themselves

....so I'd suggest picking an objective, reading as much as you can about what you have (you can answer a large number of your first questions by reading...tons of stuff here and on the web...search is a good thing), and asking for help as necessary....and most importantly, don't let my opinion, run you off

...but, (there's always a but) be realistic, again no offense, but posting all those pics and asking what all is wrong with your car and how to fix it under a thread very generally titled "Help with my 68 Mustang", is just not very realistic
So what do you think? Want to focus on seeing if it will run? Just a thought, and my $.02.....