When car is in motion and I try to stop my brakes go straight to the floor

In order to save myself some money, which is now debateable, I changed the rear brake drums on my car. The reason for the change was that while driving one day recently, the rear of the car started to sway as if fishtailing. When taking of the left rear wheel and drum, it was clear that the bearings were shot. In addition, the race and other components of the bearings had melted to the spindle. In an effort to fix my car, I decided to replace both rear drums as well as spindles. This included replacing the brake shoes as well.
Removing all of the items in questions was fairly straight forward. Putting them back together was a different story. The spindles both went on with ease. I also replaced the ABS line going into each spindle on the back as well. This was easy as well.
The brake shoes were not bad in getting them on but took a little longer. I looked at several diagrams and pictures I took from before I removed them for guidance.
The issue arises when I tried to put the new drum over the new spindle. Most resources stated that these should slide right on. This was not the case. I triple checked that the parts I bought were the correct ones, and it appears they are. That being said, it took a rubber mallet, and basically the same amount of energy it took to get the old ones off, to get the new ones on.
The new brake shoes were always in the way. On both sides it took several attempts, of putting on and pulling off the new drums until I got what I thought was right. In the first attempts, the wheel would not even move when I got the drum all the way on. I had to use a hammer to get them off again, and actually had to purchase a new drum again because I do not have a press and purchased drums with wheel bearings included. These were damaged when pulling off the new drum, probably pulling it off crooked.
At any rate, none of the articles I used mentioned an adjuster, which I did nothing with.
When I trusted the car out for the first trial run, the rear left wheel turned somewhat while on the jack, but not nearly the one and a half turn that some resources suggested it should do. The rear right side was fine. After driving, there was a significant smell and smoke/steam coming from rear left tire. I pulled the tire and drum off again, this time by removing the spindle. Once the drum and spindle were off, the drum spun fine, so I am guessing the brake shoes are the culprit.
When I pulled all of it off on this last time, the brake drum backing plate came off as well. I tried to find another one, but could not. I put everything back together using the spindle to hold the rear backing plate on this time. I also had to replace this left rear brake line, the steel part since it broke.
The last caveat to all of this is that in order to get both rear drum s on, it required disconnecting the emergency brake. It was too tight and essentially pulling the new brake shoes. I have not reconnected the emergency brake.
As far a driving now goes, there is minimal smell from before, but it is there, and the brake pedals require pumping in order to get the brakes to work. The first push is all the way to the floor and subsequent brake pedal pushes add the necessary resistance to stop.

I know there is a lot here, but if you can decipher all I have done, that is great. There are several questions I have however related to all of this:
1) Is it okay to attach the old brake drum backing plate using the spindle?
2) How do I use the adjustor to adjust the brake shoes? (I had a hard time getting the shoes to align on the wheel cylinder)
3) how do I tell if the new bearings I put on are bad? (The smell, visually, etc.)

Why doesn't my brake pedal have any pressure after just changing the brakes?

I was driving my car went to apply my brake when I noticed the brake pedal go all the way to the floor before it started slowing down. I went to a friend and we checked the pads and disc they are fine as with the fluid. We lifted the car and found that the front passenger caliper was not applying any pressure, so we changed the caliper to no joy. Could it be the brake master cylinder? I do have pressure going to the other three brakes.

There is no ABS light on.

Brake pedal goes all the way to the floor.

I know the brakes need to be done (rotars need replacing and was planning on doing this in a week or so) but today I went to brake and there was no pressure on the pedal and I came to a very slow skidding stop (thankful I didnt collide with the vehicle in front) - what's suddenly gone wrong?

Yep, fluid on the inside of the rim on driver's side. Thanks for the prompt response.

My car was working fine and then the other day I turned it on and all of a sudden I had to push the brakes down much longer to get it to stop. When I checked the brake fluid, it was about empty. I put more in, but the brakes didn't work any better. I've still been using my car (I am a college student with no money) and the fluid hasn't gone down again so I'm pretty sure it's not a leak. I tried bleeding the brakes on my own but was only able to get one. As far as I can tell, there's no other symptoms like noises or anything, it just takes much longer to stop and the reservoir was empty when I looked. I don't want to take it to a mechanic and have them tell me I need all new everything if it's not that serious (I simply can't afford it). Plus, I need to drive about five hours in two days. What do I need to do?