I'm New to the 'PC Scene' and I NEED Help

Okay, the main things you'll need to understand at least mildly well are:
Motherboard (AKA Mobo)
CPU (Processor)
CPU Cooler
RAM (Memory)
GPU (Graphics card)
Storage (Hard Drive, SSD, etc.)
PSU (Power Unit)
Operating System [Windows, Mac OS, Linux (Ubuntu, Mint, etc.), etc.]
Case

Motherboard:
For the motherboard, there are the main things that you'll need to look at to see if it can support: a) your CPU, b) your RAM, c) the GPU, and d) the form factor, AKA the size. You'll also need to know whether it has enough fan headers to support all your case fans.

To check and see if it can support your CPU, the main thing you'll be looking for is the socket type of the CPU that you want to get. You have to check the socket type of the CPU you want to get.
Example: I have an i5-4590 @ 3.3 GHz
My CPU has a socket type of LGA 1150. Only processors of this type will fit into this socket.

Next, I'll want to see if the motherboard I've chosen can support the RAM that I want.
Most games these days don't require any more than 8GB of RAM -- the ones that do require up to 8GB as minimum RAM are near to nonexistent.
Seeing as you want to game on this PC, you'll want to get around 8GB (probably in the form of two 4GB sticks of RAM).
Your RAM has to be supported by your motherboard. There are several main things to look for when looking for compatible motherboards and RAM:
RAM Type (DDR, DDR2, DDR3, DDR4) - the type of RAM supported on the motherboard is extremely important as RAM of different types won't go into other type slots. The current most common type of RAM is DDR3.
RAM Speed (1333, 1600, 1866, etc.) - the Speed that the RAM runs at is important as a motherboard can only support a range of speeds. Most common speeds for DDR3 include 1333MHz. 1600MHz, and 1866MHz (I personally prefer 1600).
RAM Amount (2GB, 4GB, 8GB, etc.) - The amount of RAM is important for obvious reasons.

The easiest of all - you need to find out whether the GPU can go onto your mobo. As long as your motherboard has a PCIe slot (also known as PCI-Express slot), you can fit a high end graphics card on it (for the most part).

Last of all, you need to know the form factor of the motherboard. Form factors include ATX, Mini ITX, Micro ATX, EATX, SSI EEB, etc.
The most popular of these form factors are ATX, Micro ATX, and Mini ITX (the smallest of these is Mini ITX).
I personally prefer the ATX form factor over the other two as it's bigger, easier to handle, and has more everything (depending on which manufacturer you buy from).
You can choose from all of these.

CPU (Processor):
There's a lot of little things to know about CPUs (including power usage, speed, overclockability, socket type, etc.)
I personally deal only with Intel processors as I prefer them over AMD processors.

All you really need to know about the CPU that I haven't already told you is mostly for when you've developed more of a knowledge in the area which requires some light research.

CPU Cooler:
CPU coolers keep the CPU at low enough temps (normally around 30C-40C on idle and 60C-70C under load) so that it'll last longer and it'll perform as it should.
Mostly, unless you're overclocking, you don't need any to buy any other cooler for your CPU (if it's Intel, if it's an AMD processor I would buy a cooler).

RAM (Memory):
Memory is what you'll need so that you can run lots of programs, essentially. When you're gaming, if you have enough RAM then you'll do better than if you have less RAM.

There really isn't anything I haven't said about RAM that you should know about that I haven't already told you above in the motherboard section.

GPU (Graphics Card):
The better the GPU and the CPU, the higher the FPS you're going to get in a game. The GPU is essential to this especially when playing more GPU intensive games.

There really is a lot of information about GPUs that you'll have to look up. I can't fit it all into here.

Storage:
There are two main types of storage, HDDs and SSDs. In a gaming PC, I'd recommend getting both, although if you're more on budget, a build without an SSD would be fine.

HDDs are the larger hard drives that you see while the solid state drives (SSDs) cost more for less space although can perform faster operations as they don't rely on physical movement.

PSU:
PSUs are the power to your PC. If you get a bad PSU that doesn't perform well or you get a PSU that can't support your system, you're buggered.

There are several main manufacturers that people trust including Corsair, XFX, and Antec (there are more, though).

Operating System:
The operating system is what you will rely on to do anything really. Examples include Mac OS, Windows, and Open Source Software (AKA Linux that includes many different little ones). If you're going for Linux, then you'll probably want to look at all the different individual OSSs that are out there.

Case:
Finally, you'll want a case that'll fit your mobo's form factor while also fitting everything else that you want into it.
You get what you pay for, especially in the area of cases.
You'll want to find ones that have good airflow while also having good cable management.




If you need, I can build you a PC based on your needs. I won't literally build the PC, but I can build you a list of pieces that you'll want so you can order them and build them yourself.