Do I have to see all that stuff on the side of the screen?

All that stuff on the side of the screen is called Blocks.  Some Blocks are required, for example the navigation block, some are informational, and some are just for fun.

You do not have to see the blocks that are not absolutely necessary for the operation of this site.  You can turn them off in your user settings.

Go to "my account" and click on the "edit" tab.  Scroll down until you find "Block configuration" and uncheck the ones you would like to turn off.  The blocks necessary for the operation of this site are not in the list so you can turn them all off if you like.