Do yourself a huge favor and do a clean install of Windows 10, not a upgrade install from 7 - 10.
Also, before installing Windows 10 do a search and download drivers for Windows 10. Search for all of them (chipset, ethernet/wi-fi, display, sata, usb, etc). Also do that for software, too, just to make sure their a no specific Windows 10 versions yo need.
Never hurts to play it safe and avoid headaches now or down the road with conflicts, etc.
As far as games go in Windows 10, I've had no issues with Steam, Origin, GOG or Ubisoft games on my PC.
A few older games may need to be run in compatibility mode, but probably not that many att all at this time.
Just check each game's supported o.s. on their store page or the developers websites.