A bit reckless giving advice, aren’t we?
We don’t know if OP has personal data in the windows drive, or copies thereof, and yet, you write:
If you plan to switch over all at once, during the install, tell Linux to use the entire drive (ie, do a full format). That will completely remove Windows during the install.
Also:
If you are going to dual boot, don’t dual boot on a single drive. Windows likes to fuck with other things on the same drive as it, including other Windows installs.
Would you please enlighten me about why you shouldn’t dual boot on a single drive? I, and millions of others have been happily doing it for decades. As a matter of fact I’m willing to bet some money that that’s precisely the most common desktop setup in the world for Linux. The major caveat is that sometimes Windows upgrades/updates won’t respect your dual boot setup, which is usually trivial to fix.
Vertical distress signal.