So this laptop is fully managed by you, ie there is no IT department that set it up and remotely tracks it?
In that case I recommend either:
(1) Wiping the disk and reinstalling windows. This gives the new user an environment that's standard and nothing can be blamed on you or found of your old files.
... or ...
(2) Buy a new/clean disk and reinstall windows. Same as above, but might be easier/simpler/preferred. A 120GB SSD is minimum for Win10, they're pretty cheap, I suggest going for 240GB if you can anyway. Any brand name unit will be good enough, unless you know you have requirements otherwise.
I suggest wiping and reinstalling because "deleting" files and user accounts on Windows (and most other operating systems) does not actually "delete" them, it simply unlists them. The next guy can potentially recover your files, including saved web browser login credentials and cookies (giving them access to eg your email).
This also avoids them having any issues with Windows 10 being annoying because of any changes you made during your use. Or at least it shifts the blame

Windows 10 will be Windows 10, especially when it comes to printing.
EDIT: If you're not already aware: Windows 10 auto-detects keys and auto-activates itself most of the time these days. It looks are your hardware IDs, asks Microsoft's server "have we seen these before?" and silently activates if it has done so. This is almost always the case if the computer came with Win10 pre-installed (ie if you didn't spend a few hundred $$$ on a separate retail Win10 key). Surprisingly painless.