Your motherboard definitely isn't x58.
With your lack of knowledge your better off buying a new premade again.
Yes because the rest of us we're born with this knowledge. We've all got to start somewhere.
First you need to do a lot of research into your current system. You wont have an Intel x58 Motherboard with an AMD CUP for starters.
To find out exactly what is in your current PC, you can open her up. This will help you to identify the motherboard and PSU.
To find out the CPU download and run the CPUz tool. This will also help to identify your RAM.
Your Graphics card can be confirmed using the similar GPUz tool. Both available from a quick Google.
Check out the System Builders guides on Toms. There are plenty of guides on just about every aspect of making and upgrading a computer.