Woah, that's a ton of questions. To answer them fully would take books :)
It seems like there are certain memorized systems that people remember when they play. Do people actually recall a series of steps during chess? If so, how do you combat all of the different ways your opponent could move? What's the point of memorizing defenses if your opponent has likely researched the same defenses and strategies that you plan to use?
Yes, there are opening systems. A system in chess is a set of opening moves you can play vs practically anything your opponent does. This is just to get you past the opening though, and doesn't help with strategy in general.
*Edit -- if you mean a thinking process there are some out there. In very generally speaking they help you to avoid oversights. For example a good "system" for beginners to adopt is to make sure their intended move is safe before playing it. E.g. noticing all your opponents possible responses that are either a check or a capture. If you still like your intended move then you can play it. This is hard to do every move but practice makes it easier :)
Often in a game between peers (for me anyway) both sides will know in general what the other is aiming for... but that doesn't stop it from working :) Just wanted to use this as a place to say in chess your opponent always has a choice... your job is to make sure their choice is only between bad and worse 
As a simple example:
At first, I was not future oriented when playing chess. I focused too much on capturing pieces but not actually seeking out my opponents king. Recently, I have improved because I now put more focus on checking my opponent.
Yes, a general goal is important to have in mind as you play. Checkmate is usually the overall or final goal. What strategy gives you is little victories to aim for between the beginning and checkmate.
For example in the opening what you want to accomplish is gain some central space by placing (and maintaining) at least one pawn in a center square. You want to bring your pieces (in chess a piece is a non-pawn) off their home squares (generally where they influence the center as well) as efficiently as possible (thus the axiom don't move a piece twice in the opening). And to castle your king to safety.
Pawns are a big part of strategy. It's certainly useful to know the different types like doubled, passed, isolated, majorities, and backward pawns. As well as pawn breaks. Wiki has some good illustration of all these.
Seeing that it's impossible for me to predict the next couple moves that my opponenet will make, I don't see how planning ahead is possible. Everytime I try to make a plan, I always have to consider what my opponent will do, and that in it itself is usally enough for me to just throw away any plan I have. How do peope make plans? What mentality should I have?
Planning ahead is more about reading the differences between the positions and aiming for those small strategic gains... such as saddling your opponent with a weak doubled or backward pawn. Perhaps you're ahead in development so your plan is to open the position with a pawn break. Maybe in an endgame you have a pawn majority on the queenside and your plan is to make a passed pawn. These are all very common and good plans (it's the execution that will make them work or not :)
There have been many books written on chess strategy, and that learning combined with experience is what will improve you there. In your games though as you're starting out there is a big need for fundamentals. A spot-on strategy about your pawn majority doesn't mean much if you blunder your knight away in the process.
The biggest of these fundamentals is checking what your opponent's last move threatened every time. And double checking if your intended move is safe every time. Of course this is very hard at first, but the more you do it the more natural it becomes. Be sure you're playing games with enough time so you're allowed to practice this every move.
Here are some examples where before you think about any kind of strategy you have to ask what new squares are affected by white's last move.
For more on tactics such as the pin you can look here:
And for a great resource on strategy and all things chess (besides this site) here's Dan Heisman's page:
http://danheisman.home.comcast.net/~danheisman/Articles/Articles.html
I'm 18 years old and I've never really played chess until now. In the past two weeks I made it a goal to learn basic chess strategy, but I don't know where to start. I played chess for many hours every day and I still could not win a single game. I have googled chess tips and I still cannot win. I've gotten really close to winning before, but it still seems as though I'm missing something important. When I research chess tips and strategies, complicated "defenses" always come up. It seems like there are certain memorized systems that people remember when they play. Do people actually recall a series of steps during chess? If so, how do you combat all of the different ways your opponent could move? What's the point of memorizing defenses if your opponent has likely researched the same defenses and strategies that you plan to use? At first, I was not future oriented when playing chess. I focused too much on capturing pieces but not actually seeking out my opponents king. Recently, I have improved because I now put more focus on checking my opponent.
My issue is that I don't know how to balance focusing between protecting my own pieces and trying to capture those of my opponents, and setting up a "plan" to check mate my opponent. Seeing that it's impossible for me to predict the next couple moves that my opponenet will make, I don't see how planning ahead is possible. Everytime I try to make a plan, I always have to consider what my opponent will do, and that in it itself is usally enough for me to just throw away any plan I have. How do peope make plans? What mentality should I have?