Depends—will you be doing anything else apart from gaming & browsing on it?
You will probably want an external backup drive anyway, and/or you might want to setup remote backup also on eg OneDrive, Google Drive etc.
If you have much data to transfer from an old system, then a "
toaster" will make that simple.
If you might have other USB bits n pieces to plug in or charge, then a
powered USB Hub is useful.
I personally couldn't work without a 2nd monitor, but I use my PC for work as well as play. There's very little support for extra monitors in games.
If you're in a carpeted area, then something to keep the PC off the ground will keep it cleaner, reducing your maintenance frequency. One of our experts may advise better, but you'll probably eventually need some compressed air, and also liquid + microfiber cloth for cleaning your monitor screen.
Got a mousepad?
That's a fine system tho, should keep you smiling for years—best of luck with it