Hello everyone! I bought an clone Uno 3 starter kit and its a lot of fun! I also bought a programming arduino book as well. I know basic features on my R3, but as a beginner I still have a lot to learn. For example, I don't know what the RX and TX pins act as. I know it is for back and forth communication, but nothing more than that. If someone could explain this I would be most grateful! Thank you! 
Welcome to the group.
You need to do some reading.
Google is your friend.
The first hit when I searched for 'arduino tx rx' was the arduino serial reference page where it is all described in perfect detail.
Some pins can perform other functions. The RX/TX pins are first and foremost digital pins, just like the others. However, they can also be used to transmit or receive serial data. Other pins can be used for used for SPI communications, or PWM, or if you do not require any of these, all of them can be used as plain old digital pins.
All the suggestions above provide very good guidance, however to help get you started I will try to explain.
First: most (nearly every) pin on the Uno can perform different functions. Which function a particular pin performs is defined in the setup() function.
To your question:
The Tx and Rx pins are special because there is hardware circuits connected to them to aid in communicating between devices.
Tx transmits
Rx receives
In a typical setup the connections might be:
My Uno Pin Rx would be connected to your Uno Pin Tx
My Uno Pin Tx would be connected to your Uno Pin Rx
Think of the Tx like a flashlight and Rx a set of eyes (human). Now consider you are using the light to transmit morse code. The flashlight would go on and off in a particular sequence to send a letter (i.e "A") The human seeing this can decode the morse code back to the letter "A".
The return message is similar but the original receiver now uses his/her flashlight to send the morse code.
BTW computers don't use morse code but use ASCII code, but the concept is the same.
Also if you are sending messages to an LCD display, you may only need:
Your Uno Tx connected to the LCD Rx
as there is no return message as many LCDs only receive.