Just click on "Start" select "Run" and type in "explorer.exe" to see what is on your machine though there are likely more than a few folders and lots of files. Understand that there are probably dozens of programs on your computer and in some cases to properly open the file may require special software so that the data can be properly viewed as in a way all the computer stores are 0s and 1s. It is knowing how to read these whether you are looking at a text file, an image's compressed encoding, audio that is stored how it is, etc.
You can try to open it if it is on your PC. I would note that there can be exceptions like if someone decides to password-protect or encrypt something that may require unlocking.
Can anyone please give me the easiest way to access all files,programs etc. on my computer? I get so frustrated. If it is on my pc i should be able to open it right?