Get rid of GarageBand if you have it installed, that thing takes up a ton of space. So does iMovie.
As for your "shrinking" disk space, you installed all of Photoshop, MS Office and iPhoto (with over 5 gigs worth of pics), three of the biggest HD space-eating apps available. Each of those apps has tons of files that go with it. MS Office alone has tons of templates, clip art, dictionaries, libraries.
The OS is also setting up cache files and organizing things to make itself run faster and more efficiently. Be aware that every new computer has "burn in" time where it does this kind of stuff.
Get rid of GarageBand and iMovie if they are present and see if that helps.
And honestly 128 gb for a modern computer is tiny. My gaming PC has a 1 terabyte hard drive, as does this 27" iMac I use at work.
As for your "shrinking" disk space, you installed all of Photoshop, MS Office and iPhoto (with over 5 gigs worth of pics), three of the biggest HD space-eating apps available. Each of those apps has tons of files that go with it. MS Office alone has tons of templates, clip art, dictionaries, libraries.
The OS is also setting up cache files and organizing things to make itself run faster and more efficiently. Be aware that every new computer has "burn in" time where it does this kind of stuff.
Get rid of GarageBand and iMovie if they are present and see if that helps.
And honestly 128 gb for a modern computer is tiny. My gaming PC has a 1 terabyte hard drive, as does this 27" iMac I use at work.