Congrats on the purchase and welcome to the site.
Building or assembling a car isn't rocket science and there is more than one way to do it. Since I don't know what the status is right now I will just throw some things out there;
The very first thing to do is spend some quality time unpacking ALL of the boxes and figure out what you have, what you don't have, what is usable and what isn't
Generally I start with making the car a roller complete with suspension front and rear. Keep in mind that you will have to wait until the car is assembled to get the front end aligned, however you can "rough it in". I would also install the front and rear brake assemblies.
Once you have a good roller then I run all of the brake and fuel lines, also if you have a wiring harness, now is a good time to route it, you can also install the fuel tank and filler neck.
Now that you have all that, install the dash and the steering column. Note that if the windshield isn't in that a good thing, makes it much easier however remember that you MUST install the trim clips in the front and rear window channels before installing the glass because once the glass is in it is very difficult if not impossible to install the clips
At this point I would install the drive train, you don't have to put a drive shaft in it but you can if you like.
With the drive train in you can install the master cylinder (with power booster if it is a PB car) as well as the exhaust manifolds/headers. You don't need to do the fill exhaust until almost done.
You can now begin to attach all of the other sub systems (wiring, brake lines, fuel lines, etc.), you can also install the instrument cluster and connect all the interior wiring.
At this point if you haven't installed the cooling and PS system you can do that. Now you can start the car and make sure everything works, no leaks, etc. This is a good time to fix anything that needs to be fixed, rerouted, etc.
Once you have all this done you can install/assemble all of the body panels and gap them as you desire.
Once you are happy with the panel fitment you can move onto the glass, stripes, vinyl top, etc.
Now you are ready to put the carpet in, the headliner, rear speaker/s, package tray and the interior as well as the door handles, license plate mount, antenna, etc. Believe it or not, it is this part that will take the most time.
Once you have all this done, you can bleed the brakes and get it aligned and you are good.
I am sure others will have a different process but the end result is the same. Also, while this all seems relatively straightforward, it does not factor in the amount time it will take to refinish, fix and recondition all of the parts/pieces.
Hope this is helpful