My computer is really slow and i need to make it better for me 2 play some heavy games but problem is i dont know anything about computers so please help me leave email if you can

Firstly you need to ensure that your PC meets the minimum requirements for a given game. I recommend Belarc Advisor if you don't know what your PC's specifications are.
Secondly you need to ensure that you are clean of viruses and malware. Do a full antivirus scan and anti-spyware scan, I recommend Grisoft's AVG free and Lavasoft's Ad-aware as scanning and removal tools.
You also need to run the minimum amount of applications while running a game. If you have anything that runs in the background like iTunes or other non-essential programs then check that they are configured to only run when you specifically request them.
If you easily meet the hardware requirements, and you've cleared out all of your PC's background functions, and the problem persists: then you'll need to check that you don't have a hardware fault with your PC. If everything checks out, then your best option is to fully reinstall windows and avoid installing anything that you don't strictly need.
Software clutter is a very common reason for PCs to act more slowly than they should.

If you need a quick pointer to which hardware components are slowing your PC down then SiSoftware Sandra has a tool which can do this for you.