Does Audacity 2.x work well with the Windows 10? Thank you in advance for your reply!
Yes, if your computer and any external sound devices you use have hardware-matched audio drivers for Windows 10.
So if you buy a new computer that came with Windows 10 and only use the built-in sound device, everything should be fine.
If you are upgrading to Windows 10 from previous Windows, or use an older external sound device that only has drivers for previous Windows, there is a chance that Audacity will say it cannot find any audio devices. Please see this page for more information Windows 10 OS - Audacity Wiki.